Wikipedia:Vital articles/Level/5/Technology

Overview
Level 1 Level 2 Level 3 Level 4 Level 5

Level 5 Sublists

People History Geography Arts Philosophy and religion Everyday life Society and social sciences Biology and health sciences Physical sciences Technology Mathematics

Improve a random level 5 vital article in Technology

Vital articles is a list of subjects for which Wikipedia should have corresponding high-quality articles. It serves as a centralized watchlist to track the status of Wikipedia's most essential articles. This is one of the sub-lists of the fifty thousand article Vital articles/Level 5 and is currently under construction.

Articles in the Vital list have their assessments labelled as:

• Featured articles
• Former featured articles
• A-class articles
• Good articles
• Delisted good articles
• Failed good article nominees
• B-class articles
• C-class articles
• Start-class articles
• Stub-class articles
• List-class articles
• Unassessed articles

The progress bar is auto-updated via category count, and the symbols and article counts are updated daily by User:cewbot. Please read the FAQ before modifying the article list.

Quota 3,200 articles.

Total 3,224 articles.

Class	#Articles
FA	19
GA	77
A	3
B	688
C	1,590
LIST	9
FFA	57
DGA	77
Start	793
Stub	47

General

This section contains 85 articles.

1. Technology (Level 1)
2. Applied science
3. Appropriate technology
4. Emerging technologies
5. Innovation
6. Invention (Level 4)
7. Maintenance
8. Miniaturization
9. Problem solving
10. Research and development
11. Scientific instrument
12. Simulation
13. Technological convergence
14. Technological determinism
15. Technology adoption life cycle
16. Technology and society
17. Technology assessment
18. Technology life cycle
19. Technology transfer

Creativity, Vocational education, Intellectual property and Patent are listed in the Society and Social Sciences section; Industrial design in the Arts section.
For history of technology, see History#History of science and technology section.

Engineering

This section contains 66 articles.

Basics

This section contains 15 articles.

1. Engineering (Level 2)
2. Nanotechnology (Level 4)
   1. Molecular machine
3. Nuclear technology (Level 4)
4. Technical drawing (Level 4)
5. Engineering ethics
6. Risk management
7. Engineering management
8. Engineering design process
   1. Requirements analysis
   2. Problem statement
   3. Feasibility study
9. Computer-aided design
10. Engineering economics
11. Reverse engineering

Disciplines

This section contains 51 articles.

1. Agricultural engineering
2. Applied mechanics
3. Biological engineering
   1. Biochemical engineering
   2. Biomedical engineering (Level 4)
   3. Pharmaceutical engineering
4. Ceramic engineering
5. Chemical engineering (Level 4)
   1. Chemical reaction engineering
   2. Nuclear engineering
   3. Molecular engineering
   4. Petroleum engineering
   5. Process engineering
   6. Polymer engineering
6. Civil engineering (Level 3)
   1. Architectural engineering (Level 4)
   2. Construction engineering
      1. Demolition
   3. Earthquake engineering
   4. Environmental engineering
   5. Geotechnical engineering
      1. Directional drilling
   6. Hydraulic engineering
   7. Mining engineering
   8. Structural engineering
   9. Transportation engineering
   10. Highway engineering
7. Electrical engineering (Level 4)
   1. Computer engineering
8. Energy engineering
   1. Power engineering
   2. Telecommunications engineering
   3. Electronic engineering
   4. Control engineering
   5. Radio-frequency engineering
9. Engineering physics
10. Industrial engineering (Level 4)
    1. Computer-aided engineering
    2. Manufacturing engineering
11. Mechanical engineering (Level 3)
    1. Aerospace engineering (Level 4)
    2. Mechatronics
    3. Railway engineering
    4. Marine engineering
    5. Automotive engineering
12. Military engineering (Level 4)
13. Sanitary engineering
14. Security engineering
15. Software engineering (Level 4)
16. Structural analysis
17. Systems engineering

Agriculture

This section contains 231 articles. See Agriculture in the Society category; also see History of Agriculture and related articles under History, or the Everyday life category for basic agricultural products

Basics

This section contains 11 articles.

1. Arable land
2. Crop
   1. Cash crop
   2. Nonfood crop
   3. Fiber crop
3. Agricultural machinery
4. Agricultural cycle
   1. Growing season
   2. Season extension
5. Agricultural land
6. Pasture

Academic disciplines

This section contains 11 articles.

1. Agricultural science (Level 4)
2. Agricultural chemistry
3. Agricultural economics
4. Agricultural philosophy
5. Agricultural soil science
6. Agroecology
7. Agricultural policy
8. Agricultural geography
9. Agricultural education
   1. Agricultural extension
10. Agrometeorology

• Also see Agricultural engineering in the Engineering section

Forms

This section contains 49 articles.

Agriculture

This section contains 38 articles.

1. Beekeeping (Level 4)
2. Cuniculture
3. Dairy (Level 4)
   1. Dairy farming
4. Dryland farming
5. Desert farming
6. Heliciculture
7. Rainfed agriculture
8. Extensive farming
9. Gardening (Level 4)
10. Intensive farming (Level 4)
11. Mechanised agriculture
12. Orchard (Level 4)
13. Organic farming (Level 4)
14. Genetically modified crops
15. Sustainable agriculture (Level 4)
16. Permaculture
17. Subsistence agriculture (Level 4)
18. Urban agriculture (Level 4)
19. Pastoralism
20. Plantation
21. Shifting cultivation
22. Regenerative agriculture
23. Animal-free agriculture
24. Intensive animal farming
25. Free range
26. Hydroponics
27. Sericulture
28. Viticulture
29. Fungiculture
30. Olericulture
31. Slash-and-burn
32. Vertical farming
33. Polyculture
    1. Multiple cropping
    2. Intercropping
34. Sharecropping
35. Tenant farmer

Aquaculture

This section contains 11 articles.

1. Aquaculture (Level 4)
2. Mariculture
3. Algaculture
4. Fish farming
   1. Aquaculture of catfish
   2. Aquaculture of salmonids
   3. Aquaculture of tilapia
5. Freshwater prawn farming
6. Integrated multi-trophic aquaculture
7. Marine shrimp farming
8. Seaweed farming

Pest and disease control

This section contains 25 articles.

1. Aerial application
2. Acaricide
3. Agrochemical
4. Agent Orange
5. Aldrin
6. Chemosterilant
7. DDT
8. Defoliant
9. Fumigation
10. Fungicide
11. Herbicide
12. Insecticide
13. Lindane
14. Malathion
15. Methoxychlor
16. Pest (organism)
17. Pest control
    1. Biological pest control
    2. Integrated pest management
18. Pesticide (Level 4)
19. Rodenticide
20. Scarecrow
21. Soil steam sterilization
22. Tetraethyl pyrophosphate
23. Toxaphene

Buildings and infrastructure

This section contains 29 articles.

1. Apiary
2. Barn (Level 4)
3. Farm (Level 4)
4. Garden (Level 3)
   1. Arboretum
   2. Botanical garden
   3. Chinese garden
   4. English landscape garden
   5. French formal garden
   6. Japanese garden
   7. Persian gardens
   8. Spanish garden
5. Fishery
6. Fish hatchery
7. Granary (Level 4)
8. Grain elevator
9. Greenhouse
10. Orangery
11. Paddy field
12. Pavilion
13. Plant nursery
14. Raised field
    1. Chinampa
    2. Waru Waru
15. Seedbed
16. Silo (Level 4)
17. Stable (Level 4)
18. Terrace (earthworks)
19. Ranch

Animal husbandry

This section contains 21 articles.

1. Animal husbandry (Level 3)
2. Animal slaughter
3. Breed (Level 4)
4. Culling
5. Domestication (Level 3)
6. Goat farming
7. Animal feed
   1. Fodder
      1. Hay (Level 4)
      2. Straw
   2. Forage
   3. Fish meal
8. Livestock (Level 4)
9. Pig farming
10. Poultry farming
11. Selective breeding (Level 4)
    1. Animal breeding
    2. Purebred
12. Sheep farming
13. Slaughterhouse
14. Antibiotic use in livestock

Agronomy

This section contains 29 articles.

Basics

This section contains 4 articles.

1. Agronomy (Level 4)
2. Plant breeding (Level 4)
   1. Cultivar (Level 4)
3. Crop yield

Agronomical techniques

This section contains 15 articles.

1. Nutrient management
2. Fertilizer (Level 3)
   1. Compost
   2. Vermicompost
   3. Green manure
   4. Guano
   5. Manure
3. Harvest (Level 4)
   1. Threshing
   2. Winnowing
4. Irrigation (Level 4)
5. Tillage (Level 4)
6. Silage
7. Sowing
8. Postharvest

Soil and soil management

This section contains 10 articles. See "Pedology" in Earth Science

1. Beneficial organism
2. Cover crop
3. Crop rotation
4. Mulch
   1. Plastic mulch
5. Nitrogen fixation
6. Norfolk four-course system
7. No-till farming
8. Three-field system
9. Soil salinity control

Horticulture

This section contains 22 articles.

1. Horticulture (Level 4)
2. Espalier
3. Floriculture
4. Grafting
5. Layering
6. Plant propagation
7. Pollarding
8. Pollination management
9. Pruning
10. Smudge pot
11. Topiary
12. Transplanting
13. Basal shoot
14. Pomology
15. Companion planting
16. Genetically modified tree
17. Indigenous horticulture
18. Urban horticulture
19. Hardiness (plants)
    1. Hardiness zone
20. Drought tolerance
21. Tropical horticulture

Hunting and fishing

This section contains 17 articles.

1. Fishing line
   1. Dropline
   2. Longline fishing
2. Fishing net
   1. Gillnetting
   2. Seine fishing
3. Fishing rod
   1. Fish hook
   2. Fishing lure
   3. Fishing reel
   4. Fishing float
4. Fish trap
   1. Crab trap
   2. Fishing weir
   3. Lobster trap
5. Trapping
   1. Bait (luring substance)

Trees and forestry

This section contains 6 articles.

1. Agroforestry
2. Arboriculture
3. Logging
4. Silviculture
5. Coppicing
6. Controlled burn

Agriculture, labor and economy

This section contains 8 articles.

1. Community-supported agriculture
   1. Teikei
2. Corporate farming
3. Family farm
4. Agricultural cooperative
5. Working animal
6. Agribusiness
7. Agricultural marketing

Agriculture and ecology

This section contains 3 articles.

1. Environmental impact of agriculture
2. Agricultural expansion
3. Agricultural pollution

Agricultural machinery and tools

See "Agricultural tools" and "Farm and Garden Machinery" in Technology : Machinery and tools

Biotechnology

This section contains 44 articles. See also : Selective Breeding in Agriculture; Fermentation in Biology

1. Biotechnology (Level 3)
2. Cell culture
   1. Plant tissue culture
3. Genetic engineering (Level 3)
4. Recombinant DNA
   1. Genetically modified organism (Level 4)
   2. CRISPR
   3. Molecular cloning
5. Cloning (Level 4)
   1. Somatic cell nuclear transfer
6. Gel electrophoresis (Level 4)
7. Polymerase chain reaction (Level 4)
8. Western blot
9. Cyborg
10. Whole genome sequencing
11. Tissue engineering
12. Biochip
13. De-extinction
14. Genome editing
15. Nuclear transfer
16. Pharming (genetics)
17. Biomimetics
18. DNA microarray
19. Micropropagation
20. Biological hazard
21. Bioterrorism
    1. Agro-terrorism
22. Pharmacogenomics
23. Biopharmaceutical
24. Genetic testing
25. Synthetic biopolymer
26. Biomaterial
27. Agricultural biotechnology
28. Environmental biotechnology
29. Bioreactor
30. Gene therapy
31. Stem-cell therapy
32. Antisense therapy
33. Organ printing
34. Protein engineering
35. Anaerobic digestion
36. Bioleaching
37. Biomining
38. Somatic fusion

Computing and information technology

This section contains 630 articles. For abstract topics in computer science, see Mathematics: Theoretical computer science (Level 5)

Basics

This section contains 11 articles.

1. Computing (Level 4)
2. Information technology (Level 4)
3. Abacus (Level 4)
4. Calculator (Level 4)
5. Counting board
6. Data (computer science) (Level 4)
   1. Data communication (Level 4)
   2. Metadata
7. File sharing
8. Human–computer interaction
9. Open source

Computer science

This section contains 16 articles.

1. Computer science (Level 3)
2. Artificial intelligence (Level 3)
3. Computer architecture (Level 4)
4. Computer simulation (Level 4)
5. Parallel computing (Level 4)
   1. General-purpose computing on graphics processing units
6. Augmented reality
7. Mixed reality
8. Virtual reality
9. Concurrent computing
   1. Monitor (synchronization)
10. Floating-point arithmetic
11. Real-time computing
12. Computer graphics (computer science)
    1. Color management
    2. Transform, clipping, and lighting

Computer architecture concepts

This section contains 27 articles.

1. Cache (computing)
2. Cache coherence
3. Distributed computing
   1. Computer cluster
   2. Grid computing
4. Cloud computing
5. Optical computing
6. DNA computing
7. Quantum computing
8. Von Neumann architecture
9. 8-bit computing
10. 16-bit computing
11. 32-bit computing
12. 64-bit computing
13. Endianness
14. Multithreading (computer architecture)
15. Multiprocessing
16. Instruction set architecture
    1. x86
       1. x86-64
    2. ARM architecture family
    3. IBM POWER architecture
    4. MIPS architecture
    5. Very long instruction word
17. System time
    1. Epoch (computing)
    2. Unix time

Computer security

This section contains 40 articles.

1. Computer security (Level 4)
2. Firewall (computing)
3. Transport Layer Security
4. Security bug
   1. Zero-day vulnerability
5. Denial-of-service attack
   1. Botnet
6. Copy protection
   1. Digital rights management
7. Malware (Level 4)
   1. Computer virus
   2. Computer worm
   3. Trojan horse (computing)
   4. Ransomware
   5. Spyware
8. Cryptography (Level 3)
   1. Blockchain
   2. Block cipher
   3. Brute-force attack
   4. Caesar cipher
   5. Cipher
   6. Cryptanalysis
   7. Digital signature
   8. Encryption (Level 4)
   9. Enigma machine
   10. Key (cryptography)
   11. One-time pad
   12. Public-key cryptography
       1. Diffie–Hellman key exchange
       2. RSA (cryptosystem)
   13. Symmetric-key algorithm
9. Authentication (Level 4)
   1. Password
   2. Security token
   3. Multi-factor authentication
   4. User (computing)
10. Security through obscurity
    1. Obfuscation (software)
    2. Steganography
11. Zombie (computing)

Computer hardware

This section contains 84 articles.

1. Computer hardware (Level 4)
2. Computer (Level 2)
   1. IBM PC–compatible
   2. Mainframe computer
   3. Microcomputer
   4. Mobile device (Level 4)
      1. Smartphone (Level 4)
      2. Tablet computer
   5. Personal computer (Level 4)
      1. Desktop computer
      2. Gaming computer
      3. Home computer
      4. Laptop
   6. Supercomputer (Level 4)
   7. Wearable computer
      1. Smartwatch
   8. Workstation
3. Booting
   1. BIOS
      1. UEFI
   2. Reboot
4. Processor (computing)
   1. Central processing unit (Level 4)
      1. Microprocessor
         1. Multi-core processor
   2. Coprocessor
5. Motherboard
6. Processor register
7. Floating-point unit
8. Graphics processing unit
9. Arithmetic logic unit
10. Digital signal processor
11. Bus (computing)
    1. SATA
    2. Parallel ATA
    3. Industry Standard Architecture
    4. Peripheral Component Interconnect
    5. PCI Express
    6. Front-side bus
12. Expansion card
    1. Sound card
    2. Graphics card
    3. PC Card
    4. ExpressCard
13. Modem
14. Device driver
15. Intel High Definition Audio
16. Moore's law
17. Clock rate
18. Embedded system
19. Real-time clock
20. Computer case
21. Computer cooling
22. Analog computer
23. Stored-program computer
24. Hardware acceleration
25. Plug and play
26. Input device
27. Output device

User interface

This section contains 25 articles.

1. User interface (Level 4)
2. Graphical user interface
   1. Window (computing)
   2. X Window System
3. Command-line interface
4. Cut, copy, and paste
5. Peripheral
   1. Computer keyboard
   2. Computer monitor (Level 4)
   3. Pointing device
      1. Computer mouse (Level 4)
      2. Touchpad
      3. Touchscreen (Level 4)
   4. Virtual reality headset
6. Computer port (hardware)
   1. IEEE 1394
   2. USB
      1. USB-C
   3. D-subminiature
   4. Digital Visual Interface
   5. DisplayPort
   6. HDMI
   7. VGA connector
   8. Thunderbolt (interface)
7. Webcam

Computer software

This section contains 38 articles.

1. Software (Level 4)
2. Application software
3. Chatbot
4. Database (Level 4)
   1. Data mining
   2. Big data
5. Emulator
6. Media player software
7. Mobile app
8. Open-source software (Level 4)
9. Spreadsheet (Level 4)
10. System software
11. Web application
    1. Webmail
    2. Web content management system
12. Web browser (Level 4)
13. Word processor (Level 4)
14. Desktop publishing
15. Plug-in (computing)
16. POSIX
17. GNU Project
18. Input method

Operating systems

This section contains 16 articles.

1. Firmware
2. Operating system (Level 4)
   1. Real-time operating system
3. Virtual machine
4. Kernel (operating system)
5. Job (computing)
6. Task (computing)
7. Thrashing (computer science)
8. Thread (computing)
9. Preemption (computing)
10. Process (computing)
11. Computer multitasking
12. Scheduling (computing)
13. System call
14. Time-sharing
15. Working set

Data storage and memory

This section contains 77 articles.

For units of information (bit, byte, megabyte, etc.), see Physical sciences/Basics and measurement

1. Computer file (Level 4)
2. Backup
3. Barcode (Level 4)
   1. QR code
4. File system (Level 4)
   1. HFS Plus
   2. File Allocation Table
   3. NTFS
   4. ext4
   5. ISO 9660
   6. Universal Disk Format
5. Directory (computing)
6. Filename extension
7. Data storage (Level 4)
   1. Computer data storage
   2. Cloud storage
8. RAID
9. Disk partitioning
10. Computer memory
11. Binary file
12. Text file
    1. Formatted text
    2. Plain text

File format

This section contains 26 articles.

1. File format
2. Archive file
   1. ZIP (file format)
   2. RAR (file format)
   3. 7z
3. Document file format
   1. Office Open XML
   2. OpenDocument
   3. PDF
4. Image file format
   1. GIF
   2. JPEG
   3. TIFF
   4. PNG
   5. SVG
5. Audio coding format
   1. WAV
   2. MP3
   3. Advanced Audio Coding
6. Video coding format
   1. Advanced Video Coding
   2. DivX
7. Container format
   1. MPEG-4
   2. WebM
   3. Ogg

Volatile memory

This section contains 5 articles.

1. Volatile memory
2. Random-access memory (Level 4)
   1. Dynamic random-access memory
   2. Static random-access memory
3. Virtual memory

Non-volatile memory

This section contains 23 articles.

1. Non-volatile memory
2. Read-only memory (Level 4)
3. Magnetic storage
   1. Floppy disk
   2. Hard disk drive (Level 4)
   3. Magnetic tape (Level 4)
      1. Magnetic-tape data storage
      2. VHS
      3. Videotape
      4. Betamax
4. Flash memory
   1. USB flash drive
   2. Solid-state drive
   3. Memory card (Level 4)
      1. CompactFlash
      2. SD card
      3. MultiMediaCard
      4. Universal Flash Storage
5. Optical disc (Level 4)
   1. Compact disc
   2. DVD
   3. LaserDisc
   4. Blu-ray

Networks

This section contains 73 articles.

1. Computer network (Level 4)
   1. Intranet
2. Email (Level 4)
   1. Spamming
   2. Simple Mail Transfer Protocol
   3. Internet Message Access Protocol
3. Ethernet (Level 4)
4. Router (computing) (Level 4)
5. Routing
6. Wi-Fi (Level 4)
7. Bluetooth
8. Cellular network
   1. GSM
9. Server (computing)
   1. Proxy server
   2. Web server
10. Client–server model
11. Network topology
12. Network switch
13. Network packet
14. Network interface controller
15. Node (networking)
16. Internet of things
17. Wireless mesh network
18. Content delivery network
19. Private network
20. Subnet
21. Tunneling protocol
22. Reverse proxy

Internet

This section contains 44 articles. For Internet culture, see Society and social sciences/Culture#Internet medium

1. Internet (Level 3)
2. ARPANET
3. CSS
4. Communication protocol
5. Common Gateway Interface
6. Domain name
7. File Transfer Protocol
8. Hashtag
9. HTML (Level 4)
   1. HTML5
   2. Hyperlink
10. HTTP (Level 4)
    1. HTTPS
11. Instant messaging
    1. Online chat
    2. IRC
12. Internet protocol suite (Level 4)
    1. Internet Protocol
    2. IP address
    3. IPv4
    4. IPv6
    5. Transmission Control Protocol
13. Internet service provider
14. Peer-to-peer
    1. BitTorrent
    2. Napster
15. Social media (Level 4)
    1. Blog
    2. Bulletin board system
    3. Chat room
    4. Internet forum
    5. Online dating
    6. Social networking service
    7. Usenet
16. Web 2.0
17. Search engine (Level 4)
18. Tor (network)
19. Website (Level 4)
    1. Home page
    2. Web page
    3. Wiki
20. World Wide Web (Level 4)
    1. Dark web
    2. Deep web

Specific websites and other computing services

This section contains 50 articles.

Cloud server

This section contains 2 articles.

1. Amazon Web Services
2. Google Cloud Platform

Multimedia

This section contains 5 articles.

1. Flickr
2. Netflix
3. Pornhub
4. Steam (service)
5. YouTube (Level 4)

E-commerce

This section contains 3 articles.

1. Alipay
2. Craigslist
3. Taobao

Portals/Platform sites

This section contains 3 articles.

1. MSN
2. Naver
3. Yahoo

Utility

This section contains 6 articles.

1. GitHub
2. Google Maps
3. Internet Archive
4. IMDb
5. Rotten Tomatoes
6. Wikipedia (Level 4)

Science

This section contains 1 article.

1. Berkeley Open Infrastructure for Network Computing

Search engines

This section contains 2 articles.

1. Google Search
2. Microsoft Bing

Social network and blogging

This section contains 28 articles.

1. 2channel
2. 4chan
3. Blogger (service)
4. DeviantArt
5. Discord
6. Facebook (Level 4)
7. ICQ
8. Instagram
9. Line (software)
10. LinkedIn
11. Myspace
12. Pinterest
13. Reddit
14. Slack (software)
15. Skype
16. Snapchat
17. Telegram (software)
18. Tencent QQ
19. TikTok
20. Tinder (app)
21. Tumblr
22. Twitch (service)
23. Twitter
24. Weibo
25. Vine (service)
26. VK (service)
27. WeChat
28. WhatsApp

Software development

This section contains 122 articles.

Software development: General

This section contains 63 articles.

1. Software development
2. Software prototyping
3. Reusability
4. Software portability
5. Transparency (human–computer interaction)
6. Library (computing)
7. Formal specification
8. Formal verification
9. Software design
10. Abstraction (computer science)
11. Variable (computer science)
12. Function (computer programming)
13. Pointer (computer programming)
14. Recursion (computer science)
15. Iteration
16. Computer programming (Level 4)
17. Flowchart
18. Source code
19. Bytecode
20. Object code
21. Executable
22. Parameter (computer programming)
23. Collation
24. Universal Product Code
25. Character encoding (Level 4)
    1. ASCII
    2. Mojibake
    3. Unicode
       1. UTF-8
26. Error correction code
27. Compiler (Level 4)
28. Interpreter (computing)
29. Control flow
30. Macro (computer science)
31. Regular expression
32. Calling convention
33. Programming language (Level 4)
34. Programming paradigm (Level 4)
    1. Functional programming (Level 4)
    2. Structured programming (Level 4)
    3. Modular programming
    4. Object-oriented programming (Level 4)
    5. Declarative programming
    6. Imperative programming
    7. Logic programming
35. API
    1. Carbon (API)
    2. Cocoa (API)
    3. Open Database Connectivity
    4. Windows API
       1. DirectX
          1. Direct3D
    5. OpenGL
    6. Vulkan
36. Software testing
37. Software bug
38. Debugging
39. Application checkpointing
40. Exception handling
41. Version control
42. Patch (computing)
43. Software maintenance
44. Software documentation

Programming languages

This section contains 41 articles.

1. Syntax (programming languages)
2. Metasyntax
3. Backus–Naur form
4. Type conversion
5. Data type
6. Delimiter
7. Operator overloading
8. Language binding
9. Low-level programming language
   1. Machine code
   2. Assembly language (Level 4)
10. High-level programming language
    1. C (programming language) (Level 4)
    2. C++
    3. C Sharp (programming language)
    4. Objective-C
    5. Delphi (software)
    6. Haskell
    7. Java (programming language) (Level 4)
    8. Kotlin (programming language)
    9. Lisp (programming language)
    10. Lua (programming language)
    11. Scala (programming language)
    12. Swift (programming language)
    13. Visual Basic (.NET)
11. Shading language
12. R (programming language)

Data modeling languages

This section contains 1 article.

1. SQL

Markup languages

This section contains 1 article.

1. XML

Scripting languages

This section contains 6 articles.

1. Python (programming language)
2. Ruby (programming language)
3. PHP
4. Perl
5. JavaScript (Level 4)
6. Shell script

"Historical" languages

This section contains 6 articles.

1. ALGOL
2. BASIC
3. Pascal (programming language)
4. Fortran
5. Ada (programming language)
6. COBOL

Artificial intelligence concepts

This section contains 18 articles.

1. AI alignment
2. Artificial general intelligence
3. Neural network (machine learning)
4. Computer chess
5. Computer Go
6. Computer vision
7. Existential risk from artificial intelligence
8. Generative artificial intelligence
9. Large language model
10. Machine learning
    1. Deep learning
11. Natural language processing
    1. Speech recognition
    2. Machine translation
12. Philosophy of artificial intelligence
13. Technological singularity
14. Turing test
15. Weak artificial intelligence

Specific hardware

This section contains 34 articles.

See also video game hardware section under games for early Home Computers

1. Amazon Kindle
2. Amiga
3. Arduino
4. Chromebook
5. Commodore 64
6. Deep Blue (chess computer)
7. iPad
8. iPhone (Level 4)
9. iPod
10. Mac (computer) (Level 4)
    1. iMac
11. PC-98
12. Raspberry Pi
13. Samsung Galaxy
14. Walkman
15. ZX Spectrum

Early computers

This section contains 18 articles.

1. Analytical engine
2. Antikythera mechanism
3. Atanasoff–Berry computer
4. Atlas (computer)
5. Colossus computer
6. Difference engine
7. EDSAC
8. EDVAC
9. ENIAC (Level 4)
10. IBM Personal Computer
11. IBM 7030 Stretch
12. Manchester computers
13. Harvard Mark I
14. TRS-80
15. UNIVAC I
16. Whirlwind I
17. Z3 (computer)
18. Apple II

Specific software

This section contains 58 articles.

Artificial Intelligence

This section contains 2 articles.

1. AlphaGo
2. ChatGPT

Browsers

This section contains 5 articles.

1. Firefox
2. Google Chrome
3. Internet Explorer
4. Microsoft Edge
5. Safari (web browser)

Communication

This section contains 2 articles.

1. Gmail
2. Microsoft Outlook

Development

This section contains 2 articles.

1. "Hello, World!" program
2. Visual Studio

Multimedia

This section contains 9 articles.

1. Adobe Creative Suite
   1. Adobe Flash
   2. Adobe Photoshop
2. GarageBand
3. GIMP
4. Inkscape
5. iTunes
6. Microsoft Paint
7. VLC media player

Office and data management

This section contains 11 articles.

1. Adobe Acrobat
2. Emacs
3. LibreOffice
4. Microsoft Office
   1. Microsoft Excel
   2. Microsoft PowerPoint
   3. Microsoft Word
5. MySQL
6. TeX
7. WinRAR
8. Vim (text editor)

Operating Systems

This section contains 19 articles.

1. Android (operating system) (Level 4)
2. iOS
3. DOS
   1. MS-DOS (Level 4)
4. Mac operating systems
   1. Classic Mac OS
   2. macOS
5. Microsoft Windows (Level 4)
   1. Windows 3.1
   2. Windows 9x
   3. Windows NT
      1. Windows XP
      2. Windows 7
      3. Windows 10
6. Symbian
7. Unix (Level 4)
8. Unix-like
   1. Linux (Level 4)
      1. Debian

Science and Engineering

This section contains 2 articles.

1. AutoCAD
2. MATLAB

System

This section contains 3 articles.

1. GDK
2. KDE
3. Wine (software)

Virtualization

This section contains 3 articles.

1. Java virtual machine
2. VirtualBox
3. VMware

Electronics

This section contains 116 articles. For topics in electromagnetism, see Physics:Electromagnetism

Electronics: General

This section contains 9 articles.

1. Electronics (Level 3)
   1. Analogue electronics
   2. Digital electronics
2. Circuit design (Level 4)
   1. Electronic design automation
   2. Printed circuit board (Level 4)
   3. SPICE
3. Electronic circuit
   1. Multimeter

Components

This section contains 36 articles.

1. Electronic component
2. Amplifier (Level 4)
   1. Operational amplifier
   2. Vacuum tube (Level 4)
3. Capacitor (Level 4)
   1. Ceramic capacitor
   2. Electrolytic capacitor
   3. Film capacitor
   4. Leyden jar
   5. Supercapacitor
   6. Variable capacitor
4. Diode (Level 4)
   1. Light-emitting diode (Level 4)
5. Electrical connector (Level 4)
6. Inductor (Level 4)
7. Power supply (Level 4)
   1. Current source
   2. Voltage source
8. Resistor (Level 4)
   1. Potentiometer
9. Switch (Level 4)
   1. Knife switch
   2. Relay (Level 4)
   3. Rotary switch
10. Transducer
    1. Actuator
       1. Solenoid
    2. Sensor (Level 4)
       1. Avalanche photodiode
       2. Photodiode
       3. Photomultiplier tube
       4. Phototube
       5. Stretch sensor
       6. Thermistor
       7. Thermocouple
11. Transformer (Level 4)

Consumer electronics

This section contains 3 articles.

1. Consumer electronics (Level 4)
2. AC adapter
3. Remote control (Level 4)

Digital logic

This section contains 16 articles.

1. Asynchronous circuit
2. Logic gate
   1. AND gate
   2. Digital buffer
   3. Inverter (logic gate)
   4. NAND gate
   5. NOR gate
   6. OR gate
   7. XOR gate
   8. XNOR gate
3. Adder (electronics)
   1. Binary multiplier
   2. Subtractor
4. Flip-flop (electronics)
5. Synchronous circuit
   1. Clock domain crossing

Functional circuits

This section contains 14 articles.

1. Bridge circuit
   1. Wheatstone bridge
2. Electronic oscillator
   1. Clock generator
      1. Clock signal
   2. Crystal oscillator
   3. Variable-frequency oscillator
3. Frequency mixer
4. Gyrator
5. Negative impedance converter
6. Power inverter
7. Rectifier
   1. Diode bridge
8. Voltage regulator

Semiconductors

This section contains 14 articles.

1. Semiconductor device (Level 3)
2. Integrated circuit (Level 3)
   1. Application-specific integrated circuit
   2. Charge-coupled device (Level 4)
   3. Field-programmable gate array
   4. System on a chip
      1. Network on a chip
   5. Very-large-scale integration
3. Transistor (Level 4)
   1. Bipolar junction transistor
   2. Field-effect transistor
      1. MOSFET
   3. Transistor–transistor logic
   4. CMOS

Signal processing

This section contains 17 articles.

1. Signal processing (Level 4)
   1. Digital signal
2. Analog-to-digital converter
3. Digital-to-analog converter
4. Filter (signal processing) (Level 4)
   1. All-pass filter
      1. Lattice phase equaliser
   2. Band-pass filter
   3. Mechanical filter
   4. High-pass filter
   5. Low-pass filter
5. Multiplexing
6. Noise (electronics)
   1. Signal-to-noise ratio (Level 4)
7. Oscilloscope (Level 4)
8. Sampling (signal processing)
   1. Nyquist–Shannon sampling theorem

Signal transmission

This section contains 7 articles.

1. Antenna (radio) (Level 4)
   1. Antenna array
2. Electromagnetic shielding
   1. Faraday cage
3. Transmission line
   1. Coaxial cable
   2. Waveguide (Level 4)

Energy

This section contains 174 articles.

Energy: General

This section contains 6 articles.

1. Energy development
   1. Electrification
2. Fire (Level 2)
3. Propellant
4. Renewable energy (Level 3)
5. Sustainable energy

Fuel

This section contains 25 articles.

1. Fuel (Level 4)
2. Biofuel (Level 4)
   1. Biomass (energy)
   2. Charcoal (Level 4)
3. Fossil fuel (Level 3)
   1. Coal (Level 3)
   2. Coke (fuel)
   3. Fracking
   4. Natural gas (Level 3)
      1. Liquefied natural gas
      2. Liquefied petroleum gas
   5. Oil well (Level 4)
      1. Petroleum reservoir
      2. Oil platform
4. Hydrogen economy
5. Oil refinery (Level 4)
   1. Aviation fuel
      1. Jet fuel
   2. Diesel fuel
   3. Fuel oil
   4. Gasoline (Level 4)
   5. Kerosene (Level 4)
   6. Liquid fuel
6. Nuclear fuel
   1. Nuclear fuel cycle

Heating and cooling

This section contains 12 articles.

1. Heating, ventilation, and air conditioning (Level 4)
   1. Heat pump
2. Air conditioning (Level 4)
   1. Evaporative cooler
   2. Passive cooling
   3. Windcatcher
3. Boiler
4. Fan (machine)
   1. Ceiling fan
5. Heat exchanger
6. Refrigeration (Level 3)
   1. Yakhchāl

Lighting

This section contains 13 articles.

1. Candle (Level 4)
2. Electric light (Level 3)
   1. Flashlight
   2. Fluorescent lamp
   3. Incandescent light bulb (Level 4)
   4. Neon lighting
3. Gas lighting
   1. Gas mantle
4. Lantern
5. Match
6. Oil lamp
7. Prism lighting
   1. Light tube

Power generation

This section contains 41 articles.

1. Power station (Level 4)
   1. Electric generator (Level 4)
      1. Induction generator
   2. Electricity generation (Level 4)
2. Hydropower (Level 3)
   1. Hydroelectricity (Level 4)
   2. Tidal power
   3. Watermill (Level 4)
3. Microgeneration
   1. Micro-CHP
4. Nuclear power (Level 3)
   1. Fusion power
      1. Inertial confinement fusion
      2. Tokamak
   2. Nuclear reactor
      1. Breeder reactor
      2. Molten-salt reactor
      3. Heavy water reactor
      4. Small modular reactor
      5. Nuclear marine propulsion
      6. Nuclear meltdown
5. Solar energy (Level 3)
   1. Solar power (Level 4)
   2. Solar cell (Level 4)
      1. Solar panel
6. Thermal power station
   1. Boiler (power generation)
   2. Cogeneration
   3. Combined cycle power plant
   4. Concentrated solar power
   5. Cooling tower (Level 4)
   6. Fossil fuel power station
      1. Coal-fired power station
      2. Gas-fired power plant
   7. Geothermal power (Level 4)
7. Turbine (Level 4)
   1. Gas turbine (Level 4)
   2. Steam turbine (Level 4)
   3. Wind turbine (Level 4)
8. Wind power (Level 3)
   1. Windmill (Level 4)

Power storage

This section contains 14 articles.

1. Energy storage
   1. Grid energy storage
   2. Home energy storage
2. Electric battery (Level 3)
   1. Lead–acid battery
   2. Nickel–iron battery
   3. Nickel–metal hydride battery
   4. Lithium-ion battery
   5. Lithium polymer battery
   6. Alkaline battery
   7. Atomic battery
3. Fuel cell
4. Pumped-storage hydroelectricity
5. Solar fuel

Power transmission

This section contains 60 articles. See also: Electromagnetism and Electromagnetism

1. AC power plugs and sockets
2. Electric power transmission (Level 4)
3. Electric power distribution (Level 4)
4. Electrical grid (Level 4)
   1. Three-phase electric power
   2. Virtual power plant
5. Electrical wiring (Level 4)
   1. Electrical cable (Level 4)
6. Mains electricity

Concepts

This section contains 21 articles.

1. Availability factor
2. Automatic generation control
3. Backfeeding
4. Base load
5. Capacity factor
6. Demand factor
7. Droop speed control
8. Energy demand management
9. Energy return on investment
10. Electrical fault
11. Grid code
12. Load factor (electrical)
13. Load-following power plant
14. Merit order
15. Nameplate capacity
16. Peak demand
17. Electric power quality
18. Power-flow study
19. Repowering
20. Utility frequency
21. Variable renewable energy

Electricity transmission and distribution

This section contains 20 articles.

1. Demand response
2. Distributed generation
3. Distribution board
4. Dynamic demand (electric power)
5. Electrical busbar system
6. Electric power system
7. Interconnector
8. High-voltage direct current
9. Load management
   1. Electricity market
10. Mains electricity by country
11. Overhead power line
12. Smart grid
13. Substation
14. Super grid
15. Transmission system operator
16. Transmission tower
17. Utility pole
    1. Overhead cable
18. Wide area synchronous grid

Electrical protective devices

This section contains 10 articles.

1. Arc-fault circuit interrupter
2. Circuit breaker (Level 4)
3. Earth-leakage circuit breaker
4. Fuse (electrical) (Level 4)
5. Lightning rod
6. Residual-current device
7. Power system protection
8. Protective relay
9. Numerical relay
10. Sulfur hexafluoride circuit breaker

Specific energy structure

This section contains 3 articles. See "Dams" section in "Specific infrastructure" for hydroelectric power plants

1. Synchronous grid of Continental Europe
2. Eastern Interconnection
3. Western Interconnection

Industry

This section contains 216 articles. See also: "Industry" in Business and economics (Level 4)

Industry: General

This section contains 17 articles.

1. Factory (Level 4)
   1. Assembly line (Level 4)
   2. Automation (Level 4)
   3. Conveyor system
      1. Conveyor belt
   4. Industrial robot (Level 4)
   5. Interchangeable parts (Level 4)
   6. Mass production (Level 4)
   7. Mechanization (Level 4)
2. Pelletizing
3. Standardization (Level 4)
4. Waste (Level 4)
   1. Incineration
   2. Landfill (Level 4)
   3. Recycling (Level 4)
   4. Waste management (Level 4)
5. 3D printing

Food, water and health

This section contains 34 articles.

1. Air purifier
   1. Air filter
      1. HEPA
   2. Catalytic converter
   3. Respirator
      1. Gas mask
   4. Scrubber
2. Bleach (Level 4)
3. Desalination (Level 4)
4. Detergent (Level 4)
5. Laundry (Level 4)
6. Food additive
   1. Food coloring
   2. High-fructose corn syrup
   3. Sugar substitute
7. Food processing
   1. Fermentation in food processing
   2. Pasteurization (Level 4)
8. Food storage
9. Oxygen mask
10. Sanitation (Level 3)
    1. Sewage
       1. Sanitary sewer (Level 4)
       2. Sewage treatment (Level 4)
          1. Septic tank
    2. Water purification (Level 4)
11. Soap (Level 4)
12. Sterilization (microbiology)
13. Water supply network (Level 4)
    1. Aqueduct (water supply) (Level 4)
    2. Pumping station (Level 4)
    3. Qanat (Level 4)
    4. Water tower (Level 4)
    5. Well (Level 4)

Materials

This section contains 45 articles.

1. Abrasive (Level 4)
2. Ceramic (Level 4)
   1. Pottery (Level 3)
      1. Earthenware
      2. Ironstone china
      3. Lithophane
      4. Porcelain (Level 4)
      5. Stoneware
      6. Terracotta
   2. Kiln
3. Chemical vapor deposition
4. Cork (material)
5. Glass (Level 3)
   1. Borosilicate glass
   2. Float glass
   3. Fused quartz
   4. Glassblowing
   5. Glass fiber
      1. Glass wool
   6. Safety glass
   7. Soda–lime glass
6. Gutta-percha
7. Leather (Level 4)
   1. Artificial leather
   2. Hide (skin)
   3. Liming (leather processing)
   4. Parchment (Level 4)
      1. Vellum
   5. Suede
   6. Tanning (leather)
8. Mineral wool
9. Natural rubber (Level 3)
   1. Vulcanization
10. Paper (Level 3)
    1. Cardboard
    2. Papermaking
       1. Pulp (paper)
       2. Sizing
    3. Papyrus (Level 4)
    4. Tissue paper
11. Plastic (Level 3)
    1. Carbon-fiber reinforced polymer
    2. Fiberglass
    3. Injection moulding
    4. Microplastics

Chemicals

This section contains 8 articles.

1. Adhesive (Level 4)
2. Chemical plant (Level 4)
3. Composite material (Level 4)
4. Explosive (Level 3)
   1. Dynamite (Level 4)
   2. Fireworks (Level 4)
5. Lubricant
6. Petrochemical (Level 4)

Metallurgy

This section contains 48 articles.

1. Metallurgy (Level 3)
   1. Smelting (Level 4)
      1. Blast furnace
      2. Crucible
      3. Electric arc furnace
      4. Induction furnace
2. Extractive metallurgy
   1. Gold dredge
   2. Mineral processing
      1. Crusher
      2. Mechanical screening
      3. Spiral separator
      4. Stamp mill
      5. Trommel screen
   3. Rocker box
3. Metalworking (Level 4)
   1. Anvil
   2. Bellows
   3. Bending (metalworking)
   4. Metal casting
      1. Die casting (Level 4)
      2. Lost-wax casting
      3. Sand casting
   5. Drawing (manufacturing)
      1. Wire (Level 4)
   6. Electrical discharge machining
   7. Extrusion (Level 4)
   8. Forge
   9. Forging (Level 4)
      1. Power hammer
   10. Grinding (abrasive cutting)
   11. Heat treating (Level 4)
   12. Laser cutting (Level 4)
   13. Machining
   14. Metal fabrication
   15. Plating
       1. Anodizing
       2. Electroplating
       3. Powder coating
   16. Precipitation hardening
   17. Quenching
   18. Rolling (metalworking) (Level 4)
   19. Sheet metal
   20. Sintering
   21. Soldering (Level 4)
   22. Steelmaking (Level 4)
   23. Welding (Level 4)
   24. Work hardening

Textiles

This section contains 64 articles.

1. Textile (Level 3)
   1. Carding

Fabrics and fibers

This section contains 22 articles.

1. Canvas (Level 4)
2. Carbon fibers
3. Cotton (Level 3)
   1. Chino cloth
   2. Denim
   3. Muslin
4. Felt (Level 4)
5. Flannel
6. Fiber (Level 4)
7. Jute
8. Kevlar
9. Lace (Level 4)
10. Linen (Level 4)
11. Polyester (Level 4)
12. Rayon
13. Silk (Level 4)
14. Spandex
15. Thread (yarn) (Level 4)
16. Wool (Level 4)
    1. Cashmere wool
    2. Tweed
17. Yarn (Level 4)

Other techniques

This section contains 12 articles.

1. Basket weaving (Level 4)
2. Crochet (Level 4)
3. Dyeing (Level 4)
   1. Dye (Level 4)
4. Embroidery (Level 4)
5. Knitting (Level 4)
6. Macramé
7. Textile printing
8. Quilting (Level 4)
   1. Quilt
9. Sewing (Level 4)
   1. Pattern

Spinning

This section contains 12 articles.

1. Hand spinning (Level 4)
   1. Distaff
   2. Spindle (textiles)
2. Open-end spinning
3. Spinning (polymers)
   1. Spinneret (polymers)
4. Ring spinning
5. Spinning frame
   1. Water frame
6. Spinning jenny
7. Spinning mule
8. Spinning wheel

Weaving

This section contains 16 articles.

1. Loom (Level 4)
   1. Jacquard machine
   2. Pirn
   3. Power loom
   4. Shuttle (weaving)
      1. Flying shuttle
2. Weaving (Level 4)
   1. Braid
   2. Brocade
   3. Damask
   4. Plain weave
   5. Satin
   6. Songket
   7. Tapestry (Level 4)
   8. Twill
   9. Warp and weft

Infrastructure

This section contains 238 articles. See also Arts: Architecture

Basics

This section contains 2 articles.

1. Building (Level 3)
2. Infrastructure (Level 3)

Building materials

This section contains 41 articles.

1. Brick (Level 4)
   1. Fire brick
2. Cement (Level 4)
   1. Bitumen
   2. Portland cement
3. Concrete (Level 3)
   1. Asphalt concrete
   2. Concrete slab
   3. Precast concrete
   4. Prestressed concrete
   5. Ready-mix concrete
   6. Reinforced concrete
      1. Rebar
   7. Roman concrete
4. Masonry (Level 3)
   1. Brickwork
   2. Stonemasonry
5. Quarry (Level 4)
6. Scaffolding (Level 4)
7. Adobe
8. Construction aggregate
9. Clapboard
10. Mortar (masonry)
11. Lath and plaster
    1. Lath
    2. Plaster
12. Drywall
13. Rammed earth
14. Roof shingle
15. Siding (construction)
16. Stone slab
17. Tile
18. Wattle and daub
19. Wood (Level 3)
    1. Engineered wood
       1. Wood–plastic composite
    2. Lumber (Level 4)
       1. Sawmill
    3. Wood drying
    4. Woodworking (Level 4)
       1. Carpentry (Level 4)

Environmental remediation

This section contains 9 articles.

1. Environmental remediation
   1. Bioremediation
      1. Bioaugmentation
      2. Biostimulation
      3. Phytoremediation
   2. Groundwater remediation
   3. In situ chemical oxidation
   4. Soil vapor extraction
   5. Remediation of contaminated sites with cement

Infrastructure by type

This section contains 102 articles.

Architectural elements

This section contains 21 articles.

1. Arch (Level 4)
2. Buttress
   1. Flying buttress
3. Ceiling (Level 4)
4. Column (Level 4)
5. Dome (Level 4)
6. Door (Level 4)
7. Elevator (Level 4)
8. Escalator
9. Façade (Level 4)
10. Floor (Level 4)
11. Foundation (engineering) (Level 4)
12. Ladder (Level 4)
13. Lighting (Level 4)
14. Pier (architecture)
15. Roof (Level 4)
16. Room (Level 4)
17. Stairs (Level 4)
18. Vault (architecture)
19. Wall (Level 4)
20. Window (Level 4)

Coastal infrastructure

This section contains 10 articles.

1. Dock (Level 4)
   1. Dry dock
   2. Marina
2. Harbor (Level 4)
3. Lighthouse (Level 4)
4. Pier (Level 4)
   1. Maritime passenger terminal
5. Port (Level 4)
   1. Container port
6. Seawall

Ceremonial buildings

This section contains 2 articles.

1. Pagoda (Level 4)
2. Pyramid (Level 4)

Commercial buildings

This section contains 3 articles.

1. Convention center
2. Office (Level 4)
3. Warehouse (Level 4)

Mixed-use buildings

This section contains 4 articles.

1. Military base
2. Tower block (Level 4)
3. Skyscraper (Level 4)
4. Tower (Level 4)

Residential buildings and housing units

This section contains 12 articles.

1. Apartment (Level 4)
2. House (Level 4)
   1. Hut (Level 4)
   2. Igloo (Level 4)
   3. Palace (Level 4)
   4. Villa (Level 4)
3. Hotel (Level 4)
   1. Inn
   2. Motel
4. Hostel
5. Mansion
6. Shelter

Rooms and spaces

This section contains 20 articles.

1. Attic
2. Balcony
3. Basement
4. Bathroom (Level 4)
   1. Toilet (room)
      1. Public toilet
5. Bedroom (Level 4)
6. Courtyard
7. Dining room
8. Garage (residential) (Level 4)
9. Hall
10. Kitchen (Level 4)
11. Laundry room
12. Living room
13. Lobby (room)
14. Porch
15. Patio
16. Sauna (Level 4)
17. Study (room)
18. Sunroom

Portable buildings and shelters

This section contains 2 articles.

1. Tent (Level 4)
2. Yurt

Earthworks

This section contains 3 articles.

1. Earthworks (engineering)
   1. Trench
2. Underground power line

Fire protection

This section contains 3 articles.

1. Fire alarm system
2. Fire hydrant
3. Smoke detector

Hydraulic infrastructure

This section contains 10 articles.

1. Cistern
2. Dam (Level 3)
   1. Caisson (engineering)
3. Drainage (Level 4)
   1. Sluice
4. Dredging
5. Flood management (Level 4)
   1. Flood control in the Netherlands (Level 4)
6. Levee (Level 4)
7. Reservoir (Level 4)

Transport infrastructure

This section contains 12 articles. See also #Transportation section

1. Bridge (Level 3)
   1. Cantilever bridge
   2. Drawbridge
   3. Flying junction
   4. Pontoon bridge
   5. Suspension bridge
   6. Viaduct
2. Tunnel (Level 4)
   1. Underwater tunnel
   2. Tunnel construction
      1. New Austrian tunneling method
      2. Tunnel boring machine

Specific infrastructure

This section contains 84 articles.

See "Transportation" and "Energy" section for infrastructure in respective discipline

Dams

This section contains 26 articles.

1. Aswan Dam (Level 4)
2. Grand Coulee Dam
3. Grand Ethiopian Renaissance Dam
4. Hoover Dam (Level 4)
5. Itaipu Dam (Level 4)
6. Tarbela Dam
7. Three Gorges Dam (Level 4)
8. Akosombo Dam
9. Atatürk Dam
10. Bratsk Hydroelectric Power Station
11. Cahora Bassa
12. Cofferdam
13. New Croton Dam
14. Delta Works
15. Tabqa Dam
16. Fort Peck Dam
17. Grande Dixence Dam
18. Guri Dam
19. Enguri Dam
20. Kariba Dam
21. Mangla Dam
22. Nurek Dam
23. Oroville Dam
24. Rogun Dam
25. Sup'ung Dam
26. Vajont Dam

Bridges

This section contains 48 articles.

1. Akashi Kaikyo Bridge (Level 4)
2. Alcántara Bridge
3. Astoria–Megler Bridge
4. Auckland Harbour Bridge
5. Banpo Bridge
6. Bosphorus Bridge
7. Bridge of Sighs
8. Bridge of the Americas
9. Britannia Bridge
10. Brooklyn Bridge (Level 4)
11. Charles Bridge
12. Confederation Bridge
13. Danyang–Kunshan Grand Bridge
14. El Ferdan Railway Bridge
15. Forth Bridge
16. Gateshead Millennium Bridge
17. George Washington Bridge
18. Golden Gate Bridge (Level 4)
19. Great Belt Bridge
20. Great Seto Bridge
21. Humber Bridge
22. Qingdao Jiaozhou Bay Bridge
23. Kapellbrücke
24. London Bridge
25. Mackinac Bridge
26. Manhattan Bridge
27. Mehmed Paša Sokolović Bridge
28. Menai Bridge
29. Millau Viaduct
30. Minneapolis Skyway System
31. Pont Alexandre III
32. Pont du Gard
33. Pont Neuf
34. Ponte Sant'Angelo
35. Ponte Vecchio
36. Rainbow Bridge (Niagara Falls)
37. Rainbow Bridge (Tokyo)
38. Rialto Bridge
39. San Francisco–Oakland Bay Bridge
40. Si-o-se-pol
41. Stari Most
42. Sydney Harbour Bridge
43. Tacoma Narrows Bridge
44. The Iron Bridge
45. Tower Bridge (Level 4)
46. Trajan's Bridge
47. Vasco da Gama Bridge
48. Verrazzano-Narrows Bridge

Tunnels

This section contains 3 articles.

1. Channel Tunnel (Level 4)
2. Gotthard Base Tunnel
3. Seikan Tunnel

Multi-modal crossings

This section contains 5 articles.

1. Bering Strait crossing
2. Chesapeake Bay Bridge–Tunnel
3. Hong Kong–Zhuhai–Macau Bridge
4. Tokyo Bay Aqua-Line
5. Øresund Bridge

Others

This section contains 2 articles.

1. Multilevel streets in Chicago
2. List of international submarine communications cables

Machinery and tools

This section contains 294 articles.

Machinery and tools: General

This section contains 11 articles.

1. Machine (Level 4)
2. MEMS
   1. Micromachinery
   2. Nanoelectromechanical systems
3. Owner's manual
4. Robotics (Level 3)
   1. Android (robot)
   2. Automaton
   3. Robot (Level 4)
   4. Robotic arm
   5. Leg mechanism

Engines

This section contains 11 articles.

1. Engine (Level 3)
2. Electric motor (Level 3)
3. Internal combustion engine (Level 3)
   1. Diesel engine (Level 4)
   2. Petrol engine
   3. Reciprocating engine
      1. Four-stroke engine (Level 4)
      2. Two-stroke engine
   4. Pistonless rotary engine
      1. Wankel engine
4. Steam engine (Level 3)

Hydraulics and pneumatics

This section contains 26 articles.

1. Hydraulics
   1. Hydraulic cylinder
   2. Hydraulic machinery
   3. Hydraulic motor
   4. Hydraulic manifold
   5. Pump
      1. Hydraulic ram
   6. Siphon (Level 4)
2. Pipe (fluid conveyance) (Level 4)
   1. Gasket (Level 4)
   2. Valve (Level 4)
3. Plumbing (Level 4)
   1. Bidet
   2. Sink (Level 4)
   3. Toilet (Level 4)
      1. Flush toilet
      2. Portable toilet
      3. Squat toilet
      4. Toilet seat
      5. Urinal
4. Pneumatics
   1. Compressor
   2. Jackhammer
   3. Nail gun
   4. Rivet gun
   5. Vacuum pump

Machinery

This section contains 63 articles.

Farm and garden machinery

This section contains 16 articles.

1. Baler
2. Chainsaw (Level 4)
3. Combine harvester (Level 4)
4. Corn harvester
5. Cotton gin (Level 4)
6. Cotton picker
7. Cultivator (Level 4)
8. Irrigation sprinkler (Level 4)
9. Lawn mower (Level 4)
10. Planter (farm implement)
11. Reaper
12. Reaper-binder
13. Seed drill
14. Swather
15. Threshing machine
16. Transplanter

Household appliances

This section contains 35 articles.

1. Home appliance (Level 4)
2. Major appliance
3. Barbecue grill
4. Blender
5. Clothes dryer (Level 4)
6. Coffeemaker
7. Dishwasher (Level 4)
8. Furnace (central heating) (Level 4)
9. Hair dryer
10. Hair iron
11. Humidifier
12. Ironing (Level 4)
13. Juicer
14. Lock and key (Level 4)
    1. Deadbolt
    2. Disc tumbler lock
    3. Electronic lock
    4. Lever tumbler lock
    5. Pin tumbler lock
    6. Skeleton key
15. Microwave oven (Level 4)
    1. Cavity magnetron (Level 4)
16. Mixer (appliance)
17. Oven (Level 3)
    1. Convection oven
18. Refrigerator (Level 4)
19. Rice cooker
20. Sewing machine (Level 4)
21. Slow cooker
22. Stove (Level 4)
    1. Electric stove
23. Vacuum cleaner (Level 4)
24. Washing machine (Level 4)
25. Water dispenser
26. Water heating

Industrial machinery

This section contains 12 articles.

1. Centrifuge (Level 4)
   1. Ultracentrifuge
2. Crane (machine) (Level 4)
3. Forklift
4. Mill (grinding)
5. Machine tool
   1. Lathe (Level 4)
   2. Machine press (Level 4)
   3. Milling (machining)
   4. Numerical control
6. Potter's wheel (Level 4)
7. Trip hammer

Mechanisms

This section contains 61 articles.

1. Mechanism (engineering)

Flexible components

This section contains 15 articles.

1. Belt (mechanical)
2. Chain (Level 4)
3. Net (device)
   1. Mesh
      1. Sieve
4. Rope (Level 4)
   1. Knot (Level 4)
      1. List of knots
      2. Bowline
      3. Double fisherman's knot
      4. Figure-eight knot
   2. Wire rope
      1. Bowden cable
      2. Flexible shaft
5. Spring (device) (Level 4)

Rigid components

This section contains 20 articles.

1. Blade
2. Fastener (Level 4)
   1. Nail (fastener) (Level 4)
   2. Nut (hardware) (Level 4)
   3. Rivet (Level 4)
   4. Screw
   5. Washer (hardware) (Level 4)
3. Gear (Level 4)
4. Hook
5. Piston
6. Simple machine (Level 3)
   1. Inclined plane (Level 4)
   2. Lever (Level 4)
   3. Pulley (Level 4)
      1. Block and tackle
   4. Screw mechanism (Level 4)
      1. Propeller
   5. Wedge (Level 4)
   6. Wheel (Level 3)
      1. Flywheel

Simple mechanisms

This section contains 25 articles.

1. Kinematic pair
   1. Ball joint
   2. Bearing (mechanical) (Level 4)
   3. Cam follower
      1. Tappet
   4. Hinge
   5. Rack and pinion
   6. Ratchet (device)
   7. Rod end bearing
   8. Wheel and axle (Level 4)
      1. Axle (Level 4)
2. Linkage (mechanical)
   1. Clutch (Level 4)
   2. Differential (mechanical device)
   3. Epicyclic gearing
   4. Escapement
   5. Four-bar linkage
   6. Gimbal
   7. Pantograph
   8. Whippletree (mechanism)
3. Shock absorber
   1. Dashpot
4. Winch
   1. Capstan (nautical)
   2. Windlass

Tools

This section contains 122 articles.

1. Tool (Level 2)
2. Lifting equipment
   1. Hoist (device)
   2. Jack (device)

Agricultural tools

This section contains 15 articles.

1. Archimedes' screw (Level 4)
2. Flail
3. Harrow (tool) (Level 4)
4. Hoe (tool) (Level 4)
5. Machete (Level 4)
6. Mattock
7. Pitchfork
8. Plough (Level 4)
9. Rake (tool) (Level 4)
10. Roller (agricultural tool)
11. Scythe
12. Sickle (Level 4)
13. Shadoof
14. Shovel (Level 4)
15. Wheelbarrow (Level 4)

Artist's and drafting tools

This section contains 16 articles.

1. Compass (drawing tool)
2. Colored pencil
3. Crayon
4. Drafting machine
5. Drawing board
6. Easel
7. French curve
8. Modelling clay (Level 4)
9. Paint (Level 4)
   1. Acrylic paint
   2. Enamel paint
   3. Varnish
10. Brush (Level 4)
11. Pastel (Level 4)
12. Pigment (Level 4)
13. T-square

Containers

This section contains 20 articles.

1. Container (Level 4)
2. Aluminum can
3. Bag
   1. Paper bag
   2. Plastic bag
4. Barrel
5. Basket
6. Bottle
   1. Water bottle
7. Box
   1. Cardboard box
   2. Coffin
   3. Crate
   4. Wooden box
8. Envelope
9. Intermodal container
10. Packaging
11. Paper cup
12. Pressure vessel
13. Steel and tin cans

Hand tools

This section contains 15 articles.

1. Adze
2. Axe (Level 4)
3. Chalk line
4. Chisel (Level 4)
5. Clamp (tool) (Level 4)
6. Crowbar
7. Drilling (Level 4)
8. Hammer (Level 4)
9. Hook (hand tool)
10. Plane (tool) (Level 4)
11. Pliers
12. Saw (Level 4)
13. Scissors (Level 4)
14. Screwdriver
15. Wrench

Measuring instruments

This section contains 21 articles.

1. Instrumentation (Level 4)
   1. Barometer (Level 4)
   2. Calipers (Level 4)
   3. Feeler gauge
   4. Ruler (Level 4)
      1. Metre-stick
      2. Tape measure
   5. Photometer (Level 4)
   6. Spectrometer (Level 4)
      1. Optical spectrometer
   7. Thermometer (Level 4)
   8. Astrolabe
   9. Breathalyzer
   10. Calorimeter
   11. Geiger counter
   12. Odometer
   13. Seismometer
   14. Speedometer
   15. Torque wrench
   16. Vernier scale
2. Polygraph

Surveying tools

This section contains 20 articles.

1. Alidade
2. Circumferentor
3. Graphometer
4. Gunter's chain
5. Laser rangefinder
   1. Lidar
6. Level (optical instrument)
   1. Inclinometer
      1. Topographic Abney level
   2. Level staff
   3. Plumb bob
   4. Spirit level
   5. Tiltmeter
7. Plane table
8. Reticle
9. Stadimeter
   1. Stadia mark
10. Surveyor's wheel
11. Theodolite (Level 4)
    1. Total station

Writing tools

This section contains 11 articles.

1. Blackboard
2. Eraser
3. Ink (Level 4)
4. Pen (Level 4)
   1. Ballpoint pen
   2. Fountain pen
   3. Marker pen
   4. Quill
5. Pencil (Level 4)
   1. Pencil sharpener
6. Whiteboard

Media and communication

This section contains 110 articles. See also Arts: Literature; Society: Mass media
Physical and analog media are also included here

Media and communication: Basics

This section contains 36 articles.

1. Media (communication)
2. Bulletin board
3. Communications satellite (Level 4)
4. Display device
   1. Cathode-ray tube (Level 4)
   2. Flat-panel display (Level 4)
      1. Liquid-crystal display (Level 4)
      2. microLED
      3. OLED
      4. Plasma display
   3. Projection screen
5. Document
6. Image (Level 4)
7. Image scanner (Level 4)
8. Mail (Level 3)
   1. Courier (Level 4)
   2. Postage stamp (Level 4)
   3. Pigeon post
   4. Autopen
9. Portable media player
10. Sound recording and reproduction (Level 4)
    1. Cassette tape
    2. Loudspeaker (Level 4)
    3. Phonograph
       1. Phonograph record
    4. Headphones
    5. Microphone (Level 4)
11. Speech synthesis (Level 4)
12. Typewriter (Level 4)
    1. QWERTY
13. Video (Level 4)
    1. Digital video
       1. Digital video recorder
    2. Video camera (Level 4)
    3. Videocassette recorder
14. Wireless

Broadcasting

This section contains 35 articles.

1. Broadcasting (Level 3)
2. Radio (Level 3)
   1. Amateur radio (Level 4)
   2. Antenna tuner
   3. Radio broadcasting (Level 4)
      1. FM broadcasting
      2. AM broadcasting
      3. Shortwave radio
   4. Radio receiver
      1. Crystal radio
      2. Superheterodyne receiver
      3. Transistor radio
   5. Software-defined radio
   6. Transmitter
   7. Walkie-talkie
3. Television (Level 3)
   1. Analog television
      1. NTSC
      2. PAL
      3. SECAM
   2. Color television
   3. Digital television
      1. ATSC standards
      2. Digital multimedia broadcasting
      3. Digital Terrestrial Multimedia Broadcast
      4. DVB
      5. ISDB
   4. High-definition television
   5. Ultra-high-definition television
   6. Mechanical television
   7. Cable television (Level 4)
   8. Satellite television (Level 4)
   9. Streaming media
   10. Streaming television
   11. Terrestrial television

Printing

This section contains 16 articles.

1. Printing (Level 3)
2. Audiobook
3. Book (Level 2)
   1. ISBN
4. Ebook
   1. E-reader
5. Manuscript
   1. Codex
   2. Scroll (Level 4)
6. Photocopier (Level 4)
7. Printer (computing) (Level 4)
8. Printing press (Level 4)
   1. Font
   2. Movable type
   3. Print on demand
   4. Typesetting

Telecommunications

This section contains 23 articles.

1. Telecommunications (Level 3)
2. Demodulation
3. Fax
4. Modulation (Level 4)
   1. Amplitude modulation
   2. Frequency-hopping spread spectrum
   3. Frequency modulation
   4. Frequency-shift keying
   5. Phase modulation
5. Pager
6. Submarine communications cable
7. Telegraphy (Level 4)
   1. Electrical telegraph
   2. Flag semaphore
8. Telephony
   1. Code-division multiple access
   2. Telephone (Level 3)
   3. Landline
   4. Mobile phone (Level 3)
   5. Satellite phone
   6. SIM card
9. Text messaging (Level 4)
10. Videotelephony

Medical technology

This section contains 43 articles.

Diagnostic technologies

This section contains 4 articles.

1. DNA profiling (Level 4)
2. Electrocardiography (Level 4)
3. Electroencephalography
4. Endoscopy (Level 4)

Imaging

This section contains 6 articles.

1. Medical imaging (Level 3)
2. CT scan
3. Magnetic resonance imaging (Level 4)
4. Medical ultrasound (Level 4)
5. Positron emission tomography
6. Radiography (Level 4)

Devices

This section contains 15 articles.

1. Artificial cardiac pacemaker
2. Artificial organ (Level 4)
3. Catheter
4. Cervical collar
5. Dentures (Level 4)
6. Hearing aid
7. Orthopedic boot
8. Orthopedic cast
9. Prosthesis (Level 4)
10. Reflex hammer
11. Sling (medicine)
12. Splint (medicine)
13. Stethoscope (Level 4)
14. Tourniquet
15. Ventilator

Equipment

This section contains 7 articles.

1. Adhesive bandage
2. Bandage (Level 4)
3. Dressing (medicine)
4. Hypodermic needle
5. Retainer (orthodontics)
6. Stretcher
7. Syringe (Level 4)

Mobility aids

This section contains 2 articles.

1. Crutch
2. Wheelchair (Level 4)

Surgical instruments

This section contains 5 articles.

1. Forceps
2. Scalpel
3. Surgical suture
4. Retractor (medicine)
5. Tweezers

Techniques

This section contains 2 articles.

1. Cardiopulmonary bypass (Level 4)
2. Kidney dialysis

Transport

This section contains 2 articles.

1. Ambulance (Level 4)
2. Air medical services

Military technology

This section contains 290 articles.

Military technology: General

This section contains 8 articles.

1. Weapon (Level 3)
2. Military technology (Level 4)
3. Booby trap
   1. Punji stick
   2. Trou de loup
4. Siege engine
   1. Battering ram (Level 4)
   2. Siege tower

Countermeasures

This section contains 27 articles.

1. Stealth technology (Level 4)
2. Missile defense

Armour

This section contains 11 articles.

1. Armour (Level 3)
   1. Body armor
      1. Bulletproof vest (Level 4)
      2. Chain mail (Level 4)
      3. Plate armour (Level 4)
   2. Vehicle armour
      1. Reactive armour
2. Helmet (Level 4)
   1. Combat helmet
3. Shield (Level 4)
   1. Scutum

Fortification

This section contains 14 articles.

1. Fortification (Level 3)
   1. Bastion fort
      1. Glacis
      2. Ravelin
      3. Tenaille
   2. Castle (Level 4)
      1. Motte-and-bailey castle
      2. Bastion
      3. Curtain wall (fortification)
      4. Gatehouse
      5. Keep
   3. Defensive wall (Level 4)
      1. Palisade
      2. Rampart (fortification)

Melee weapons

This section contains 38 articles.

1. Battle axe (Level 4)
2. Brass knuckles
3. Club (weapon) (Level 4)
   1. Baton (law enforcement)
   2. Mace (bludgeon)
   3. War hammer
4. Flail (weapon)
   1. Nunchaku
5. Sai (weapon)
6. Tonfa

Knives

This section contains 9 articles.

1. Bayonet (Level 4)
2. Knife (Level 3)
3. Dagger (Level 4)
4. Hunting knife
5. Pocketknife
   1. Swiss Army knife
   2. Switchblade
6. Throwing knife
7. Utility knife

Polearms

This section contains 8 articles.

1. Polearm
2. Dagger-axe
   1. Ji (polearm)
3. Halberd
4. Naginata
5. Partisan (weapon)
6. Spear (Level 4)
   1. Pike (weapon)

Swords

This section contains 11 articles.

1. Sword (Level 4)
2. Claymore
3. Cutlass
4. Dao (Chinese sword)
5. Gladius
6. Katana (Level 4)
7. Longsword
8. Rapier (Level 4)
9. Sabre
10. Scimitar
11. Talwar

Ranged weapons

This section contains 101 articles.

1. Boomerang (Level 4)
2. Gun
3. Javelin
   1. Harpoon
   2. Spear-thrower
4. Sling (weapon) (Level 4)
5. Slingshot

Archery

This section contains 11 articles.

1. Bow and arrow (Level 4)
   1. Compound bow
   2. Longbow
   3. Recurve bow
2. Arrow
   1. Arrowhead
   2. Fletching
3. Bowstring
4. Crossbow (Level 4)
   1. Repeating crossbow
5. Quiver

Artillery

This section contains 12 articles.

1. Artillery (Level 4)
2. Cannon (Level 4)
   1. Field gun
   2. Howitzer
   3. Limbers and caissons
   4. Mortar (weapon) (Level 4)
3. Catapult (Level 4)
   1. Ballista (Level 4)
      1. Polybolos
   2. Mangonel
   3. Onager (weapon)
   4. Trebuchet

Firearms

This section contains 60 articles.

1. Firearm (Level 3)
   1. Fire lance
   2. Hand cannon
2. Handgun (Level 4)
   1. Revolver
   2. Pistol
3. Long gun
   1. Arquebus
   2. Musket (Level 4)
   3. Rifle (Level 4)
      1. Assault rifle (Level 4)
      2. Sniper rifle
   4. Shotgun (Level 4)
   5. Submachine gun
4. Machine gun (Level 4)
5. Autocannon
   1. Rotary cannon

Ammunition

This section contains 15 articles.

1. Ammunition (Level 4)
   1. Ammunition box
2. Gunpowder (Level 3)
   1. Powder keg
   2. Smokeless powder
3. Bullet
   1. Armor-piercing bullet
   2. Hollow-point bullet
   3. Tracer ammunition
4. Flechette
5. Cartridge (firearms)
   1. Sabot (firearms)
6. Shotgun cartridge
   1. Shot (pellet)
7. Shotgun slug

Mechanisms

This section contains 19 articles.

1. Breechloader
   1. Action (firearms)
      1. Automatic firearm
      2. Bolt action
      3. Burst mode (weapons)
      4. Repeating firearm
      5. Select fire
      6. Semi-automatic firearm
   2. Firing pin
   3. Magazine (firearms)
2. Gun barrel
   1. Multiple-barrel firearm
   2. Rifling
3. Muzzleloader
   1. Flintlock
   2. Matchlock
   3. Percussion cap
   4. Wheellock
4. Trigger (firearms)

Specific firearms

This section contains 9 articles.

1. AK-47
2. Chassepot
3. Dreyse needle gun
4. Gatling gun
5. Glock
6. M134 Minigun
7. M4 carbine
8. M16 rifle
9. M1911 pistol

Missiles

This section contains 11 articles.

1. Missile (Level 4)
   1. Air-to-air missile
   2. Anti-tank guided missile
   3. Cruise missile
   4. Intercontinental ballistic missile
   5. Rocket-propelled grenade
   6. Surface-to-air missile
      1. Man-portable air-defense system
2. Missile guidance
3. Multiple rocket launcher
4. Warhead

Explosive weapons

This section contains 15 articles.

1. Bomb (Level 3)
   1. Improvised explosive device (Level 4)
      1. Car bomb
   2. Detonator
   3. Fuze
      1. Contact fuze
      2. Proximity fuze
2. Cluster munition (Level 4)
3. Grenade (Level 4)
4. Land mine (Level 4)
5. Plastic explosive
6. Shaped charge
   1. Explosively formed penetrator
   2. High-explosive anti-tank
7. Thermobaric weapon

Incendiary weapons

This section contains 5 articles.

1. Greek fire
2. Flamethrower
3. Molotov cocktail
4. Napalm (Level 4)
5. White phosphorus munition

Maneuver

This section contains 9 articles.

1. Horses in warfare (Level 4)
   1. Caltrop
   2. Chariot (Level 4)
2. Infantry fighting vehicle
   1. Armoured personnel carrier
   2. Technical (vehicle)
3. Tank (Level 4)
   1. Main battle tank
4. War elephant (Level 4)

Military aviation

This section contains 45 articles.

1. Military aviation
2. Military aircraft (Level 4)
   1. Military glider
   2. Military helicopter
3. Attack aircraft (Level 4)
   1. Gunship
4. Bomber (Level 4)
   1. Strategic bomber
   2. Heavy bomber
   3. Medium bomber
   4. Interdictor
   5. Penetrator (aircraft)
5. Fighter aircraft (Level 4)
   1. Air superiority fighter
   2. Interceptor aircraft
   3. Fighter-bomber
   4. Strike fighter
6. Electronic-warfare aircraft
7. Maritime patrol aircraft
8. Multirole combat aircraft
9. Military transport aircraft
10. Airborne early warning and control
11. Reconnaissance aircraft
12. Surveillance aircraft
13. Experimental aircraft
14. Aerial refueling

Specific aircraft

This section contains 19 articles.

1. Boeing B-29 Superfortress
   1. Enola Gay
2. Boeing B-52 Stratofortress
3. Dassault Rafale
4. Embraer EMB 314 Super Tucano
5. Eurofighter Typhoon
6. Fairchild Republic A-10 Thunderbolt II
7. General Dynamics F-16 Fighting Falcon
8. Lockheed C-130 Hercules
9. Lockheed SR-71 Blackbird
10. Lockheed Martin F-22 Raptor
11. Lockheed Martin F-35 Lightning II
12. McDonnell Douglas F-15 Eagle
13. McDonnell Douglas F/A-18 Hornet
14. Mikoyan-Gurevich MiG-21
15. North American P-51 Mustang
16. Northrop B-2 Spirit
17. Panavia Tornado
18. Rockwell B-1 Lancer

Naval warfare

This section contains 21 articles.

1. Warship (Level 4)
   1. Aircraft carrier (Level 4)
   2. Battleship (Level 4)
      1. Dreadnought
   3. Corvette
   4. Cruiser
   5. Destroyer
   6. Frigate
   7. Galleon
   8. Galley (Level 4)
      1. Trireme
   9. Gunboat
   10. Ironclad warship
   11. Ship of the line (Level 4)
2. Submarine (Level 4)
3. Boom (navigational barrier)
   1. Anti-submarine net
4. Depth charge
5. Naval mine (Level 4)
6. Torpedo (Level 4)

Specific seacraft

This section contains 1 article.

1. U-boat

Less-lethal weapons

This section contains 9 articles.

1. Non-lethal weapon
2. Active Denial System
3. Baton round
4. Sonic weapon
5. Stun grenade
6. Taser
7. Tear gas
   1. Pepper spray
8. Water cannon

Weapon of mass destruction

This section contains 12 articles.

1. Weapon of mass destruction (Level 4)
2. Biological warfare (Level 4)
   1. Entomological warfare
3. Chemical weapon (Level 4)
   1. Blister agent
   2. Blood agent
   3. Nerve agent
4. Dirty bomb
5. Nuclear weapon (Level 4)
   1. Thermonuclear weapon (Level 4)
   2. Nuclear weapon design
   3. Nuclear proliferation

Navigation and timekeeping

This section contains 88 articles. For units of time (hour, day, etc.), see Physical sciences – Measurement. For maps and cartography, see Geography – Physical geography.

Navigation

This section contains 24 articles.

1. Navigation (Level 3)
2. Compass (Level 3)
   1. Compass rose
3. Cardinal direction (Level 4)
   1. North
   2. South
   3. East
   4. West
4. Celestial navigation (Level 4)
   1. Backstaff
   2. Jacob's staff
   3. Octant (instrument)
   4. Quadrant (instrument)
   5. Sextant (Level 4)
5. Dead reckoning (Level 4)
6. Gyroscope (Level 4)
7. Satellite navigation (Level 4)
   1. BeiDou
   2. Galileo (satellite navigation)
   3. Global Positioning System (Level 4)
   4. GLONASS
   5. Satellite navigation device
8. Radar (Level 3)
9. Sonar

Timekeeping

This section contains 64 articles.

1. Astronomical year numbering
2. Calendar (Level 3)
3. Clock (Level 3)
4. Leap year (Level 4)
5. Leap second
6. Future
7. Present
8. Past
9. Standard time
10. Timeline
11. Time standard
    1. Coordinated Universal Time (Level 4)
    2. Greenwich Mean Time
    3. International Atomic Time
12. Time zone (Level 4)
    1. Daylight saving time (Level 4)

Calendars

This section contains 12 articles.

1. Solar calendar
   1. Gregorian calendar (Level 4)
      1. Anno Domini
      2. Common Era
   2. Julian calendar (Level 4)
2. Lunisolar calendar
   1. Buddhist calendar
   2. Chinese calendar (Level 4)
   3. Hindu calendar
3. Lunar calendar
   1. Hebrew calendar
   2. Islamic calendar (Level 4)

Clocks

This section contains 16 articles.

1. 12-hour clock
2. 24-hour clock
3. Alarm clock
4. Atomic clock (Level 4)
5. Digital clock
6. Clock face
7. Hourglass
8. Marine chronometer
9. Pendulum clock
   1. Pendulum (Level 4)
10. Quartz clock
11. Sundial (Level 4)
12. Watch (Level 4)
    1. Pocket watch
    2. Stopwatch
13. Water clock

Months

This section contains 12 articles.

1. January
2. February
3. March
4. April
5. May
6. June
7. July
8. August
9. September
10. October
11. November
12. December

Days of the week

This section contains 8 articles.

1. Names of the days of the week
2. Monday
3. Tuesday
4. Wednesday
5. Thursday
6. Friday
7. Saturday
8. Sunday

Optical technology

This section contains 60 articles.

Optical components

This section contains 15 articles.

1. Lens (Level 3)
   1. Fresnel lens
   2. Thin lens
2. Collimator
3. Diffraction grating (Level 4)
4. Mirror (Level 4)
   1. One-way mirror
5. Optical coating
   1. Anti-reflective coating (Level 4)
6. Optical fiber (Level 4)
7. Optical filter
8. Optical isolator
9. Polarizer (Level 4)
10. Prism (optics) (Level 4)
    1. Pentaprism

Optical instruments

This section contains 16 articles.

1. Autocollimator
2. Binoculars (Level 4)
3. Glasses (Level 4)
   1. Bifocals
   2. Contact lens
4. Interferometry (Level 4)
5. Loupe
6. Magnifying glass
7. Microscope (Level 3)
   1. Electron microscope (Level 4)
      1. Scanning electron microscope
      2. Transmission electron microscopy
      3. Scanning tunneling microscope
   2. Optical microscope (Level 4)
8. Periscope
9. Projector

Lasers

This section contains 9 articles.

1. Laser (Level 3)
   1. Solid-state laser
      1. Ruby laser
      2. Nd:YAG laser
   2. Dye laser
   3. Gas laser
      1. Carbon-dioxide laser
      2. Helium–neon laser
2. Maser

Photography

This section contains 20 articles.

1. Camera (Level 3)
   1. Hidden camera
   2. Instant camera
   3. Rangefinder camera
   4. Single-lens reflex camera
      1. Digital single-lens reflex camera
   5. Twin-lens reflex camera
   6. Closed-circuit television
2. Holography (Level 4)
3. Photographic film (Level 4)
   1. Photographic plate
4. Photography (Level 3)
   1. Digital photography (Level 4)
   2. Fine-art photography (Level 4)
   3. Landscape photography
   4. Portrait photography
   5. Street photography
   6. Exposure (photography)
   7. Flash (photography)
   8. Multi-exposure HDR capture

Astronomical technology

This section contains 71 articles.

1. Astronomical catalog
2. Ephemeris
3. Star chart
4. Astronomical Almanac

Telescope

This section contains 67 articles.

1. Telescope (Level 3)
2. Reflecting telescope
   1. Cassegrain reflector
   2. Dobsonian telescope
   3. Gregorian telescope
   4. Newtonian telescope
   5. Ritchey–Chrétien telescope
   6. Schmidt–Cassegrain telescope
3. Refracting telescope
4. X-ray telescope
5. Optical telescope (Level 4)
6. Infrared telescope
7. Radio telescope (Level 4)
8. Solar telescope
9. Space telescope
10. Astronomical interferometer
    1. Aperture synthesis
11. Telescope mount
    1. Altazimuth mount
    2. Equatorial mount
12. Active optics
13. Adaptive optics
14. Eyepiece
15. Astronomical filter
16. Primary mirror
17. Gravitational-wave observatory

Space-based observatories

This section contains 15 articles.

1. Hubble Space Telescope (Level 4)
2. Spitzer Space Telescope
3. Herschel Space Observatory
4. INTEGRAL
5. Fermi Gamma-ray Space Telescope
6. James Webb Space Telescope
7. Wide-field Infrared Survey Explorer
8. IRAS
9. Chandra X-ray Observatory
10. Kepler
11. GALEX
12. Hipparcos
13. Gaia (spacecraft)
14. XMM-Newton
15. ROSAT

Ground-based observatories

This section contains 26 articles.

1. Atacama Large Millimeter Array (Level 4)
2. Mauna Kea Observatories (Level 4)
   1. Subaru Telescope
   2. Thirty Meter Telescope
   3. W. M. Keck Observatory
3. Gemini Observatory
4. Five-hundred-meter Aperture Spherical Telescope
5. LIGO
6. Virgo interferometer
7. IceCube Neutrino Observatory
8. Very Large Telescope
9. Large Binocular Telescope
10. Mount Wilson Observatory
11. Very Large Array
12. Very Long Baseline Array
13. Arecibo Observatory
14. Green Bank Telescope
15. Effelsberg 100-m Radio Telescope
16. Low-Frequency Array
17. MeerKAT
18. Square Kilometre Array
19. Extremely Large Telescope
    1. Giant Magellan Telescope
20. Wise Observatory
21. South Pole Telescope
22. Jodrell Bank Observatory

Space

This section contains 76 articles.

Basics

This section contains 20 articles.

1. Spaceflight (Level 3)
   1. Sub-orbital spaceflight
   2. Orbital spaceflight
   3. Artificial gravity
2. Spacecraft (Level 4)
3. Rocket (Level 3)
   1. Launch pad
   2. Launch vehicle (Level 4)
   3. Rocket engine (Level 4)
4. Satellite (Level 3)
5. Space station (Level 3)
6. Astronaut (Level 4)
   1. Space suit
7. Space capsule
8. Uncrewed spacecraft
9. Interstellar travel
10. Space colonization
11. Space settlement
12. Space industry
13. Asteroid mining

Programs and launch sites

This section contains 16 articles.

1. NASA (Level 4)
   1. Apollo program (Level 4)
   2. Kennedy Space Center (Level 4)
   3. Project Gemini
   4. Project Mercury
2. Soviet space program (Level 4)
   1. Baikonur Cosmodrome (Level 4)
   2. Vostok programme
   3. Voskhod programme
   4. Soyuz programme
3. Roscosmos (Level 4)
4. European Space Agency (Level 4)
5. China National Space Administration (Level 4)
6. ISRO
7. Israel Space Agency
8. JAXA

Crewed vehicles

This section contains 12 articles.

1. Apollo 11
2. International Space Station (Level 4)
3. Mir (Level 4)
4. Salyut 1
5. Space Shuttle (Level 4)
   1. Space Shuttle Challenger disaster
   2. Space Shuttle Columbia disaster
6. Saturn V (Level 4)
7. Soyuz (spacecraft) (Level 4)
8. Skylab
9. Tiangong space station
10. Vostok 1

Unmanned spacecraft

This section contains 19 articles.

1. Sputnik 1 (Level 4)
2. Sputnik 2
3. Luna 2
4. Luna 3
5. Mariner 2
6. Luna 9
7. Voyager program (Level 4)
   1. Voyager 1
   2. Voyager 2
   3. Voyager Golden Record
8. Pioneer program
   1. Pioneer 10
   2. Pioneer 11
9. New Horizons
10. Galileo project
11. Cassini–Huygens
12. Cosmic Background Explorer
13. Wilkinson Microwave Anisotropy Probe
14. MESSENGER

Rovers

This section contains 9 articles.

1. Rover (space exploration)
2. Mars rover
   1. Perseverance (rover)
   2. Curiosity (rover)
   3. Spirit (rover)
   4. Opportunity (rover)
   5. Sojourner (rover)
3. Lunar rover
   1. Lunokhod 1

Transportation

This section contains 458 articles.

Basics

This section contains 20 articles.

1. Transport (Level 2)
   1. Public transport (Level 4)
   2. Private transport
2. Travel (Level 4)
3. Airbag
4. Passenger
   1. Intermodal passenger transport
5. Freight transport (Level 4)
   1. Cargo (Level 4)
6. Induced demand
7. Seat belt
8. Traffic
   1. Traffic collision (Level 4)
   2. Traffic congestion
9. Vehicle (Level 4)
   1. Motor vehicle
   2. Alternative fuel vehicle
   3. Electric vehicle
   4. Battery electric vehicle
   5. Hybrid vehicle

Ground transport

This section contains 165 articles.

Concepts of ground transport

This section contains 22 articles.

1. Land transport
   1. Road transport (Level 4)
2. Breakdown (vehicle)
3. Charging station
4. Driving (Level 4)
5. Filling station (Level 4)
6. Parking (Level 4)
   1. Parking lot
7. Service (motor vehicle)
   1. Automobile repair shop
   2. Bus garage
   3. Car wash
   4. Rail yard
8. Rest area
9. Tire (Level 4)
10. Transport hub
    1. Bus station
    2. Bus stop
    3. Train station (Level 4)
       1. Goods station
       2. Railway platform
    4. Park and ride

Road infrastructure

This section contains 26 articles. For bridges and tunnels, see transport infrastructure in #Infrastructure section.

1. Road (Level 3)
   1. Avenue (landscape)
   2. Boulevard
   3. Byway (road)
   4. Dirt road
   5. Highway (Level 4)
      1. Controlled-access highway (Level 4)
   6. Road junction
      1. Interchange (road)
         1. Stack interchange
      2. Intersection (road)
         1. Traffic light
         2. Traffic sign
   7. Toll road
2. Footpath
3. Pedestrian crossing
4. Pedestrian zone
5. Sidewalk
6. Trail (Level 4)
7. Cycling infrastructure
   1. Bicycle boulevard
   2. Bike lane
   3. Bicycle parking rack
   4. Shared-use path
   5. Bicycle-sharing system
   6. Cycle track

Motorized road transport

This section contains 52 articles.

1. Auto rickshaw
2. Bus (Level 4)
   1. Articulated bus
   2. Bus rapid transit
   3. Coach (bus)
   4. Double-decker bus
   5. Minibus
   6. Public transport bus service
   7. School bus
   8. Trolleybus
3. Car (Level 3)
   1. Convertible
   2. Coupe
   3. Electric car
   4. Grand tourer
   5. Hatchback
   6. Limousine
   7. Luxury car
   8. Microcar
   9. Muscle car
   10. Sedan (automobile)
   11. Sports car
   12. Station wagon
   13. Supercar
   14. T-top
4. Motorcycle (Level 4)
   1. Chopper (motorcycle)
   2. Minibike
   3. Moped
   4. Scooter (motorcycle)
      1. Motorized scooter
      2. Scooter-sharing system
   5. Sports motorcycle
5. Off-road vehicle
   1. All-terrain vehicle
   2. Dune buggy
   3. Snowmobile
6. Shared transport
   1. Carpool
   2. Demand-responsive transport
7. Truck (Level 4)
   1. Flatbed truck
   2. Monster truck
   3. Pickup truck
   4. Semi-trailer truck
   5. SUV
8. Van (Level 4)
   1. Minivan
9. Vehicle for hire
   1. Motorcycle taxi
   2. Share taxi
   3. Taxi (Level 4)

Rail and cable transport

This section contains 28 articles.

1. Rail transport (Level 4)
   1. Railway track (Level 4)
      1. Elevated railway
   2. Railway electrification
2. Train (Level 3)
   1. Locomotive (Level 4)
      1. Electric locomotive
      2. Diesel locomotive
      3. Steam locomotive (Level 4)
   2. Railroad car
   3. Rolling stock
   4. Passenger train
      1. Commuter rail
   5. Rail freight transport
   6. Freight train
3. Cable transport (Level 4)
   1. Aerial tramway (Level 4)
   2. Cable car (railway)
   3. Funicular
   4. Gondola lift
   5. Ski lift
4. High-speed rail (Level 4)
5. Tram (Level 4)
   1. Interurban
   2. Light rail
6. Rapid transit (Level 4)
   1. Medium-capacity rail system
   2. Monorail (Level 4)

Animal-powered transport

This section contains 6 articles.

1. Carriage (Level 4)
2. Cart (Level 4)
3. Horsecar
4. Saddle (Level 4)
5. Stirrup
6. Stagecoach

Human-powered transport

This section contains 16 articles.

1. Bicycle (Level 3)
   1. Bicycle brake
   2. Bicycle gearing
   3. Derailleur
   4. Shifter (bicycle part)
   5. BMX bike
   6. Electric bicycle
   7. Mountain bike
   8. Penny-farthing
   9. Recumbent bicycle
   10. Tandem bicycle
2. Handcar
3. Kick scooter
4. Rickshaw (Level 4)
5. Tricycle
6. Unicycle

Specific-purpose transportation

This section contains 12 articles. For medical transport, see Medical section

1. Baby transport (Level 4)
2. Fire engine
3. Paratransit
4. Pipeline (Level 4)
5. Police car
6. Heavy equipment
   1. Bulldozer
   2. Dump truck
   3. Excavator
   4. Road roller
      1. Steamroller
   5. Tractor (Level 4)

Specific automobiles

This section contains 3 articles.

1. Ford Model T
2. Toyota Corolla
3. Volkswagen Beetle

Naval transport

This section contains 64 articles. For military watercraft, see Military technology. For pier and port, see coastal infrastructure.

1. Maritime transport (Level 4)
2. Ship (Level 3)
   1. Anchor
3. Watercraft
4. Buoy
5. Canal (Level 3)
   1. Lock (water navigation) (Level 4)
6. Barge (Level 4)
7. Boat (Level 4)
8. Canoe (Level 4)
9. Cargo ship (Level 4)
   1. Container ship
10. Ferry (Level 4)
11. Fishing vessel (Level 4)
12. Hospital ship
13. Hovercraft (Level 4)
14. Hydrofoil
15. Icebreaker
16. Kayak
17. Merchant ship (Level 4)
18. Motor ship
19. Motorboat
20. Multihull
    1. Catamaran
21. Naval architecture
22. Outrigger (nautical)
23. Passenger ship (Level 4)
    1. Cruise ship
    2. Ocean liner
24. Personal watercraft
25. Raft
26. Riverboat (Level 4)
27. Sail (Level 4)
28. Sailboat
    1. Schooner
    2. Sloop
29. Sailing ship (Level 4)
    1. Caravel
    2. Clipper
    3. Junk (ship)
30. Sailing (Level 4)
31. Shipbuilding (Level 4)
32. Steamboat (Level 4)
33. Steamship
    1. Paddle steamer
34. Submersible
    1. Diving bell
    2. Remotely operated underwater vehicle
35. Tanker (ship) (Level 4)
    1. Oil tanker
36. Tugboat

Specific piers and ports

This section contains 13 articles.

1. Port of Singapore
2. Port of Ningbo-Zhoushan
3. Port of Busan
4. Port of Rotterdam
5. Port of Jebel Ali
6. Port of Los Angeles
7. Port of New York and New Jersey
8. Port of Port Hedland
9. Port of Yokohama
10. Port of Kobe
11. Port of Hamburg
12. PortMiami
13. Port of Barcelona

Aviation

This section contains 114 articles.

Concepts of aviation

This section contains 11 articles.

1. Aviation (Level 4)
2. Aircraft (Level 3)
3. Airline (Level 4)
4. Airport (Level 4)
   1. Airport terminal
   2. Helipad
   3. Runway
5. Air traffic control (Level 4)
6. Civil aviation
   1. General aviation
   2. Parachute (Level 4)

Types of aircraft

This section contains 20 articles.

1. Aerostat
   1. Balloon (aeronautics) (Level 4)
      1. Hot air balloon (Level 4)
      2. Gas balloon
   2. Airship (Level 4)
      1. Blimp
      2. Rigid airship
         1. Zeppelin
      3. Semi-rigid airship
2. Fixed-wing aircraft (Level 4)
   1. Airplane (Level 4)
      1. Airliner
   2. Cargo aircraft
   3. Glider (aircraft) (Level 4)
   4. Jet aircraft (Level 4)
   5. Ultralight aviation
      1. Powered paragliding
3. Rotorcraft
   1. Helicopter (Level 4)
4. Unmanned aerial vehicle (Level 4)

Aircraft components

This section contains 43 articles.

1. Aircraft engine (Level 4)
   1. Auxiliary power unit
   2. Jet engine (Level 4)
      1. Turbofan
      2. Turbojet
   3. Radial engine
   4. Turboprop
   5. Turboshaft
   6. Thrust reversal
2. Aircraft flight control system
   1. Fly-by-wire
3. Airframe
   1. Aircraft fairing
   2. Empennage
   3. Fuselage
   4. Landing gear
   5. Wing (Level 4)
      1. Airfoil
      2. Wingtip device
4. Avionics
   1. ACARS
   2. Airborne collision avoidance system
   3. ARINC 429
   4. Autopilot
   5. FADEC
   6. Flight management system
   7. Flight recorder
   8. Future Air Navigation System
   9. Health and usage monitoring systems
   10. Integrated modular avionics
5. Cockpit
   1. Flight instruments
   2. Glass cockpit
6. Flight control surfaces
   1. Aileron
   2. Air brake (aeronautics)
   3. Elevator (aeronautics)
   4. Flap (aeronautics)
   5. Leading-edge slat
   6. Spoiler (aeronautics)
   7. Stabilizer (aeronautics)
   8. Trim tab
7. Line-replaceable unit

Specific aircraft

This section contains 27 articles. For military aircraft, see Military technology

1. Airbus A300
2. Airbus A320 family
3. Airbus A330
4. Airbus A350
5. Airbus A380
6. Antonov An-225 Mriya
7. Boeing 707
8. Boeing 737
9. Boeing 747
10. Boeing 767
11. Boeing 777
12. Boeing 787 Dreamliner
13. De Havilland Canada Dash 8
14. Cessna 172
15. Concorde
16. de Havilland Comet
17. Douglas DC-3
18. Douglas DC-6
19. Douglas DC-8
20. Embraer E-Jet family
21. Ilyushin Il-76
22. Lockheed Constellation
23. McDonnell Douglas DC-9
24. McDonnell Douglas DC-10
25. Mil Mi-8
26. Tupolev Tu-154
27. Wright Flyer

Airports

This section contains 13 articles.

Asia

This section contains 6 articles.

1. Beijing Capital International Airport
2. Dubai International Airport
3. Haneda Airport
4. Hong Kong International Airport
5. Indira Gandhi International Airport
6. Shanghai Pudong International Airport

Europe

This section contains 3 articles.

1. Charles de Gaulle Airport
2. Heathrow Airport
3. Sheremetyevo International Airport

North America

This section contains 4 articles.

1. Hartsfield–Jackson Atlanta International Airport
2. John F. Kennedy International Airport
3. Los Angeles International Airport
4. O'Hare International Airport

Specific transportation systems

This section contains 95 articles.

Ground transportation networks

This section contains 15 articles. See Geography/Physical for Maritime transportation network. See Society/Politic and economic for companies that operate transportation networks.

1. Intercontinental and transoceanic fixed links
2. Arab Mashreq International Road Network
3. Asian Highway Network
4. Autobahn
5. Camino de Santiago
6. Interstate Highway System
   1. U.S. Route 66
7. Roman roads
   1. Appian Way
8. Trans-African Highway network
9. Trans-European Transport Network
   1. Trans-European high-speed rail network
10. EuroVelo
11. European long-distance paths
12. Transcontinental railroad

Rapid transit

This section contains 64 articles.

Africa

This section contains 1 article.

1. Cairo Metro

Americas

This section contains 13 articles.

1. Caracas Metro
2. Mexico City Metro
3. Santiago Metro
4. TransMilenio

Brazil

This section contains 2 articles.

1. Rio de Janeiro Metro
2. São Paulo Metro

Canada

This section contains 3 articles.

1. Montreal Metro
2. Toronto subway
3. SkyTrain (Vancouver)

United States

This section contains 4 articles.

1. Chicago "L"
2. Massachusetts Bay Transportation Authority
3. New York City Subway (Level 4)
4. Washington Metro

Asia

This section contains 24 articles.

1. Dubai Metro
2. Transjakarta
3. Mass Rapid Transit (Singapore)
4. Taipei Metro
5. Tehran Metro

China

This section contains 6 articles.

1. Beijing Subway
2. Chongqing Rail Transit
3. Guangzhou Metro
4. MTR
5. Shanghai Metro
6. Shenzhen Metro

India

This section contains 5 articles.

1. Delhi Metro
2. Hyderabad Metro
3. Kolkata Metro
4. Mumbai Metro
5. Namma Metro

Japan

This section contains 6 articles.

1. Hiroshima Electric Railway
2. Nagoya Municipal Subway
3. Osaka Metro
4. Sapporo Municipal Subway
5. Toei Subway
6. Tokyo Metro

South Korea

This section contains 2 articles.

1. Busan Metro
2. Seoul Metropolitan Subway

Europe

This section contains 26 articles.

1. Athens Metro
2. Brussels Metro
3. Budapest Metro
4. Istanbul Metro
5. Kyiv Metro
6. Prague Metro
7. Vienna U-Bahn

France

This section contains 3 articles.

1. Lyon Metro
2. Paris Métro
3. Réseau Express Régional

Germany

This section contains 3 articles.

1. Berlin U-Bahn
2. Munich U-Bahn
3. S-Bahn

Italy

This section contains 2 articles.

1. Milan Metro
2. Rome Metro

Netherlands

This section contains 2 articles.

1. Amsterdam Metro
2. Rotterdam Metro

Russia

This section contains 2 articles.

1. Moscow Metro
2. Saint Petersburg Metro

Scandinavia

This section contains 4 articles.

1. Copenhagen Metro
2. Helsinki Metro
3. Oslo Metro
4. Stockholm Metro

Spain

This section contains 2 articles.

1. Barcelona Metro
2. Madrid Metro

United Kingdom

This section contains 1 article.

1. London Underground (Level 4)

High-speed rail

This section contains 11 articles.

1. Acela
2. AVE
3. China Railway High-speed
4. Eurostar
5. Frecciarossa
6. Intercity Express
7. Korea Train Express
8. Shinkansen (Level 4)
9. Taiwan High Speed Rail
10. TGV
11. Sapsan

Railway lines

This section contains 4 articles.

1. Trans-Australian Railway
2. Chinese Eastern Railway
3. Trans-Mongolian Railway
4. Trans-Siberian Railway (Level 4)

Railway services

This section contains 1 article.

1. Orient Express