Wikipedia:Vital articles/Level/5/Technology

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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.

Total articles: 2,479/3,000

General (30 articles)

1. Technology (Level 1)
2. Invention
3. Innovation
4. Applied science
5. Research and development
6. Technology and society
7. Technological determinism
8. Technology life cycle
9. Technology adoption life cycle
10. Problem solving
11. Miniaturization
12. Technology assessment
13. Technology transfer
14. Appropriate technology

Science in countries

1. Science and technology in Germany
2. Science and technology in China
3. Science and technology in Japan
4. Science and technology in Russia
5. Science and technology in France
6. Science and technology in the United States
7. Science and technology in India
8. Science and technology in the United Kingdom
9. Science and technology in Brazil
10. Science and technology in Italy
11. Science and technology in South Korea
12. Science and technology in the Soviet Union

History (4 articles)

1. Ancient Greek technology
2. List of Chinese inventions
3. Ancient Roman technology
4. Medieval Islamic inventions

See also Creativity, Vocational education, Intellectual property and Patent in the Society and Social Sciences section; Industrial design in the Arts section; History of technology, Medieval technology and History of science and technology in China in the History section.

Agriculture (219 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 (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 (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 (57 articles)

Agriculture (40 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 (Level 4)
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. Pastoral farming
    1. Permaculture
17. Subsistence agriculture (Level 4)
18. Urban agriculture (Level 4)
19. Pastoralism
20. Shifting cultivation
21. Regenerative agriculture
22. Animal-free agriculture
23. Intensive animal farming
24. Free range
25. Grazing (Level 4)
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 farming
36. Forest gardening

Aquaculture (17 articles)

1. Aquaculture (Level 4)
2. Mariculture
3. Algaculture
4. Aquaculture of giant kelp
5. Fish farming
   1. Aquaculture of catfish
   2. Aquaculture of salmonids
   3. Aquaculture of tilapia
6. Freshwater prawn farming
7. Geoduck aquaculture
8. Integrated multi-trophic aquaculture
9. Marine shrimp farming
10. Offshore aquaculture
11. Organic aquaculture
12. Raceway
13. Scallop aquaculture
14. Seaweed farming

Pest and disease control (25 articles)

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

Buildings and infrastructure (26 articles)

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

Animal husbandry (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 (30 articles)

Basics (4 articles)

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

Agronomical techniques (16 articles)

1. Nutrient management
2. Fertilizer (Level 3)
   1. Compost
   2. Vermicompost
   3. Green manure
   4. Guano
   5. Manure
   6. Urea (Level 4)
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 (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 (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
    1. Hardiness zone
20. Drought tolerance
21. Tropical horticulture

Trees and Forestry (5 articles)

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

Agriculture, Labor and Economy (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 (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 (49 articles)

1. Biotechnology (Level 3)
2. Genetic engineering (Level 3)
3. Recombinant DNA
   1. Genetically modified organism (Level 4)
   2. CRISPR
   3. Molecular cloning
4. Cloning (Level 4)
   1. Somatic cell nuclear transfer
5. Gel electrophoresis (Level 4)
6. Polymerase chain reaction (Level 4)
7. Western blot
8. Cybernetics (Level 4)
   1. Cyborg
9. Whole genome sequencing
10. Tissue engineering
11. Biochip
12. De-extinction
13. Genome editing
14. Nuclear transfer
15. Pharming
16. Synthetic biology
17. Biomimetics
18. Bioinformatics
    1. Genomics
    2. Proteomics
    3. 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. Bioremediation
31. Gene therapy
32. Stem-cell therapy
33. Antisense therapy
34. Organ printing
35. Protein engineering
36. Activated sludge
37. Anaerobic digestion
38. Bioleaching
39. Biomining
40. Somatic fusion

See also : Selective Breeding in Agriculture; Fermentation in Biology

Computing and information technology (490 articles)

For abstract topics in computer science, see Mathematics: Theoretical computer science (Level 5)

Basics (9 articles)

1. Computing (Level 4)
2. Information technology (Level 4)
3. Abacus (Level 4)
4. Calculator (Level 4)
5. Data (Level 4)
   1. Data communication (Level 4)
   2. Metadata
6. File sharing
7. Human–computer interaction

Computer science (17 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
10. Floating-point arithmetic
11. Automata theory
12. Information visualization
13. Real-time computing
14. Computer graphics
    1. Pixel

Artificial intelligence concepts (15 articles)

1. Artificial general intelligence
2. Computer chess
   1. Deep Blue
3. Computer Go
   1. AlphaGo
4. Existential risk from artificial general intelligence
5. Friendly artificial intelligence
6. Machine learning
7. Natural language processing
   1. Speech recognition
8. Artificial neural network
9. Philosophy of artificial intelligence
10. Technological singularity
11. Turing test
12. Weak AI

Computer architecture concepts (20 articles)

1. Cache
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
15. Multiprocessing
16. x86
17. x86-64
18. ARM architecture

Computer hardware (104 articles)

1. Computer hardware (Level 4)
2. Computer (Level 2)
   1. Personal computer
   2. Home computer
   3. Desktop computer
   4. Laptop
      1. 2-in-1 PC
   5. Mobile device
      1. Tablet computer
      2. Wearable computer
   6. Gaming computer
   7. IBM PC compatible
   8. Mainframe computer
   9. Supercomputer
3. Booting (Level 4)
   1. BIOS
   2. Multi-booting
   3. Reboot
4. Central processing unit (Level 4)
   1. Microprocessor
      1. Multi-core processor
5. Motherboard
6. Processor register
7. Graphics processing unit
8. Arithmetic logic unit
9. Digital signal processor
10. Bus
    1. Serial ATA
11. Controller
12. Expansion card
    1. Sound card
    2. Graphics card
13. Modem
14. Device driver
15. Intel High Definition Audio
16. Moore's law
17. Embedded system
18. Real-time clock
19. Computer case
20. Computer cooling
21. Analog computer
22. Stored-program computer

Specific computers (39 articles)

1. Amazon Kindle
2. Amiga
3. Amstrad CPC
4. Asus Eee PC
5. Chromebook
6. Commodore 64
7. iMac
8. iPad
9. Macintosh
10. MSX
11. Netbook
12. PC-9800 series
13. ThinkPad
14. Timex Sinclair 1000
15. ZX Spectrum

Early computers (24 articles)

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

User interface (23 articles)

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

Computer software (59 articles)

1. Software (Level 4)
2. Application software
3. Database (Level 4)
   1. Data mining
   2. Big data
4. Mobile app
5. Open-source software (Level 4)
6. Spreadsheet (Level 4)
7. System software
8. Web application
   1. Webmail
   2. Web content management system
9. Web browser (Level 4)
   1. Firefox
   2. Google Chrome
   3. Internet Explorer
   4. Microsoft Edge
   5. Opera (web browser)
10. Word processor (Level 4)
11. Desktop publishing
12. Plug-in
13. Adobe Flash

Operating systems (35 articles)

1. Firmware
2. Operating system (Level 4)
3. Android (Level 4)
4. iOS (Level 4)
5. DOS
   1. MS-DOS (Level 4)
6. Linux (Level 4)
7. Macintosh operating systems (Level 4)
   1. Classic Mac OS
   2. macOS
8. Microsoft Windows (Level 4)
   1. Windows 3.1x
   2. Windows 9x
      1. Windows 95
      2. Windows 98
   3. Windows NT
      1. Windows XP
      2. Windows Vista
      3. Windows 7
      4. Windows 10
9. Unix (Level 4)
10. Virtual machine
    1. Java virtual machine
11. Kernel
12. Job
13. Task
14. Thrashing
15. Thread
16. Preemption
17. Process
18. Computer multitasking
19. Scheduling
20. System call
21. Time-sharing
22. Working set

Utility software (2 articles)

1. Antivirus software
2. Backup software

Computer security (32 articles)

1. Computer security (Level 4)
2. Firewall
3. Transport Layer Security
4. Security bug
5. Cybercrime
6. Zombie
7. Copy protection
   1. Digital rights management
8. Malware (Level 4)
   1. Computer virus
   2. Computer worm
   3. Trojan horse
   4. Spyware
9. Phishing
10. Denial-of-service attack
11. Cryptography (Level 3)
    1. Block cipher
    2. Brute-force attack
    3. Caesar cipher
    4. Cipher
    5. Cryptanalysis
    6. Digital signature
    7. Encryption (Level 4)
    8. Enigma machine
    9. Key
    10. One-time pad
    11. Public-key cryptography
        1. Diffie–Hellman key exchange
        2. RSA
    12. Symmetric-key algorithm
12. Authentication (Level 4)
13. Password

Data storage and memory (59 articles)

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

1. Computer file (Level 4)
2. Barcode (Level 4)
3. File system (Level 4)
   1. HFS Plus
   2. File Allocation Table
   3. NTFS
   4. ext4
   5. ISO 9660
   6. Universal Disk Format
4. Directory
5. Filename extension
6. File format
   1. .exe
   2. Document file format
      1. Office Open XML
      2. OpenDocument
      3. PDF
   3. Image file format
      1. GIF
      2. JPEG
      3. TIFF
      4. PNG
      5. SVG
   4. Audio coding format
      1. WAV
      2. MP3
      3. AAC
   5. Video coding format
      1. MPEG-4
      2. Advanced Video Coding
7. Data storage (Level 4)
   1. Computer data storage
8. Cloud storage
9. RAID
10. Disk partitioning
11. Computer memory
12. Volatile memory
    1. Random-access memory (Level 4)
       1. Dynamic random-access memory
       2. Static random-access memory
    2. Virtual memory
13. Non-volatile memory
    1. Read-only memory (Level 4)
    2. Magnetic storage
       1. Floppy disk
       2. Hard disk drive (Level 4)
       3. Magnetic tape (Level 4)
    3. 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
14. Binary file
15. Text file
    1. Formatted text
    2. Plain text

Networks (66 articles)

1. Computer network (Level 4)
2. OSI model
3. Email (Level 4)
   1. Spamming
   2. Simple Mail Transfer Protocol
   3. Internet Message Access Protocol
4. Ethernet (Level 4)
5. Router (Level 4)
6. Routing
7. Wi-Fi (Level 4)
8. Bluetooth
9. Cellular network
   1. GSM
10. Server
11. Client–server model
12. Network switch
13. Network packet
14. Network interface controller
15. Node
16. Internet of things

Internet (46 articles)

1. Internet (Level 3)
2. ARPANET
3. CSS
4. Communication protocol
5. Common Gateway Interface
6. File Transfer Protocol
7. Hashtag
8. HTML (Level 4)
   1. HTML5 (Level 4)
9. Hypertext Transfer Protocol (Level 4)
   1. HTTPS
   2. Internet meme
10. Online chat
11. Internet protocol suite (Level 4)
    1. Internet Protocol
    2. IP address
    3. IPv4
    4. IPv6
    5. Transmission Control Protocol
12. Internet Relay Chat
13. Internet service provider
14. Online shaming
15. Peer-to-peer file sharing
    1. BitTorrent
    2. EDonkey network
    3. Napster
16. Social networking service
17. Viral video
18. Web 2.0
19. Search engine (Level 4)
20. Tor
21. Website (Level 4)
    1. Wiki
22. World Wide Web (Level 4)
    1. Dark web
    2. Deep web

Internet in countries (10 articles)

1. Internet in China
2. Internet in India
3. Internet in the United States
4. Internet in Brazil
5. Internet in the United Kingdom
6. Internet in Germany
7. Internet in France
8. Internet in Russia
9. Internet in Japan
10. Internet in South Africa

Software development (109 articles)

General (65 articles)

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

Programming languages (44 articles)

1. Syntax
2. Metasyntax
3. Backus–Naur form
4. Type conversion
5. Delimiter
6. Operator overloading
7. Language binding
8. Low-level programming language
   1. Machine code
      1. Instruction set architecture
         1. IBM POWER instruction set architecture
         2. MIPS architecture
         3. Very long instruction word
   2. Assembly language (Level 4)
9. High-level programming language
   1. C (Level 4)
   2. C++
   3. C#
   4. Objective-C
   5. Delphi
   6. Haskell
   7. Java (Level 4)
   8. Kotlin
   9. Lisp
   10. Prolog
   11. Scala
   12. Swift
   13. Visual Basic .NET
10. Shading language

Data modeling languages (1 article)

1. SQL

Markup languages (1 article)

1. XML

Scripting languages (6 articles)

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

"Historical" languages (7 articles)

1. ALGOL
2. BASIC
3. Pascal
4. Fortran
5. Ada
6. COBOL
7. Logo

Electronics (82 articles)

For topics in electromagnetism, see Physics:Electromagnetism

Basics (22 articles)

1. Electronics (Level 3)
   1. Analogue electronics
   2. Digital electronics
   3. Consumer electronics (Level 4)
2. Current source
3. Electrical cable (Level 4)
4. Voltage source
5. Digital signal
6. Sensor (Level 4)
7. Signal processing (Level 4)
8. Nyquist–Shannon sampling theorem
9. Noise
   1. Signal-to-noise ratio (Level 4)
10. Electronic circuit
11. Circuit design (Level 4)
    1. Electronic design automation
    2. SPICE
12. Oscilloscope (Level 4)
13. Multimeter
14. Multiplexing
15. Remote control (Level 4)
16. Faraday cage

Components (60 articles)

1. Electronic component
2. Semiconductor device (Level 3)
   1. Transistor (Level 4)
   2. Bipolar junction transistor
   3. Transistor–transistor logic
   4. CMOS
   5. MOSFET
   6. Logic gate
   7. Flip-flop
   8. Diode (Level 4)
      1. Light-emitting diode (Level 4)
3. Integrated circuit (Level 3)
   1. Very Large Scale Integration
   2. Field-programmable gate array
4. Electric battery (Level 3)
   1. Lead–acid battery
   2. Nickel–metal hydride battery
   3. Lithium-ion battery
   4. Alkaline battery
5. Amplifier (Level 4)
6. Operational amplifier
7. Transmission line
   1. Coaxial cable
8. Antenna (Level 4)
9. Antenna array
10. Capacitor (Level 4)
    1. Ceramic capacitor
    2. Electrolytic capacitor
    3. Film capacitor
    4. Leyden jar
    5. Supercapacitor
    6. Variable capacitor
11. Cavity magnetron (Level 4)
12. Electrical connector (Level 4)
13. Filter (Level 4)
    1. Mechanical filter
    2. High-pass filter
    3. Low-pass filter
14. Digital-to-analog converter
15. Analog-to-digital converter
16. Inductor (Level 4)
17. Power supply (Level 4)
18. AC adapter
19. Mains electricity
20. AC power plugs and sockets
21. Ground
22. Printed circuit board (Level 4)
23. Resistor (Level 4)
    1. Potentiometer
24. Switch (Level 4)
    1. Circuit breaker (Level 4)
    2. Fuse (Level 4)
    3. Relay (Level 4)
    4. Rotary switch
25. Transformer (Level 4)
26. Vacuum tube (Level 4)
27. Waveguide (Level 4)
28. Wire (Level 4)
29. Transducer
30. Voltage regulator

Engineering (69 articles)

Basics (18 articles)

1. Engineering (Level 2)
2. Nanotechnology (Level 4)
3. Nuclear technology (Level 4)
4. Technical drawing (Level 4)
5. Engineering ethics
6. Risk analysis
7. Engineering management
8. Engineering design process
   1. Needs analysis
   2. Problem statement
   3. Feasibility study
   4. Engineering optimization
9. Computer-aided design
10. Engineering economics
11. Engineering statistics
12. Engineering research
13. Reverse engineering
14. Engineering studies

Disciplines (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
   7. Plastics engineering
6. Civil engineering (Level 3)
   1. Architectural engineering (Level 4)
   2. Construction engineering
   3. Earthquake engineering
   4. Environmental engineering
   5. Geotechnical engineering
   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. Microwave engineering
   6. 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 (Level 4)
12. Military engineering (Level 4)
13. Sanitary engineering
14. Security engineering
15. Software engineering (Level 4)
16. Structural analysis
17. Systems engineering

Industry (206 articles)

See also: "Industry" in Business and economics (Level 4)

Basics (15 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. Standardization (Level 4)
3. Waste (Level 4)
   1. Landfill (Level 4)
   2. Recycling (Level 4)
   3. Waste management (Level 4)
4. 3D printing

Energy and fuel (111 articles)

1. Fire (Level 2)
   1. Candle (Level 4)
2. Fuel (Level 4)
3. Aviation fuel
   1. Jet fuel
4. Biofuel (Level 4)
   1. Charcoal (Level 4)
5. Biomass
6. Fossil fuel (Level 3)
   1. Coal (Level 3)
   2. Natural gas (Level 3)
      1. Liquefied natural gas
   3. Petroleum (Level 3)
      1. Asphalt
      2. Diesel fuel
      3. Fuel oil
      4. Gasoline (Level 4)
      5. Kerosene (Level 4)
      6. Liquefied petroleum gas
      7. Oil platform
      8. Oil refinery (Level 4)
      9. Oil well (Level 4)
7. Liquid fuel
8. Nuclear power (Level 3)
9. Propellant
10. Renewable energy (Level 3)
    1. Geothermal power (Level 4)
    2. Hydropower (Level 3)
       1. Hydroelectricity (Level 4)
       2. Watermill (Level 4)
    3. Solar energy (Level 3)
       1. Solar power (Level 4)
       2. Solar cell (Level 4)
    4. Wind power (Level 3)
       1. Windmill (Level 4)
11. Sustainable energy

Electricity generation, transmission and distribution (76 articles)

See also: Electromagnetism and Electromagnetism

1. Electric light (Level 3)
   1. Incandescent light bulb (Level 4)
   2. Fluorescent lamp
   3. Neon lighting
2. Electric power transmission (Level 4)
3. Electric power distribution (Level 4)
4. Electrical grid (Level 4)
5. Electric generator (Level 4)
6. Electricity generation (Level 4)
7. Electrification (Level 4)
8. Power station (Level 4)
9. Turbine (Level 4)
   1. Gas turbine (Level 4)
   2. Steam turbine (Level 4)
   3. Wind turbine (Level 4)
10. Cooling tower (Level 4)

Concepts (25 articles)

1. Availability factor
2. Automatic generation control
3. Backfeeding
4. Base load
5. Capacity factor
6. Demand factor
7. Droop speed control
8. Economic dispatch
9. Electric power
10. Demand management
11. EROEI
12. Fault
13. Home energy storage
14. Grid storage
15. Grid code
16. Load factor
17. Load-following power plant
18. Merit order
19. Nameplate capacity
20. Peak demand
21. Power quality
22. Power-flow study
23. Repowering
24. Utility frequency
25. Variability

Electricity generation (9 articles)

1. AC power
2. Cogeneration
3. Combined cycle
4. Induction generator
5. Micro CHP
6. Microgeneration
7. Rankine cycle
8. Three-phase electric power
9. Virtual power plant

Electricity transmission and distribution (19 articles)

1. Demand response
2. Distributed generation
3. Dynamic demand
4. Electrical busbar system
5. Electric power system
6. Interconnector
7. High-voltage direct current
8. High-voltage shore connection
9. Load management
10. Mains electricity by country
11. Power line
12. Power storage
13. Pumped hydro
14. Smart grid
15. Substation
16. Super grid
17. Transmission system operator (TSO)
18. Transmission tower
19. Utility pole

Protective devices (7 articles)

1. Arc-fault circuit interrupter
2. Earth-leakage circuit breaker
3. Residual-current device (GFI)
4. Power system protection
5. Protective relay
6. Numerical relay
7. Sulfur hexafluoride circuit breaker

Food, water and health (21 articles)

1. Bleach (Level 4)
2. Desalination (Level 4)
3. Detergent (Level 4)
4. Laundry (Level 4)
5. Food storage
   1. Pasteurization (Level 4)
   2. Refrigeration (Level 3)
6. Sanitation (Level 3)
   1. Sanitary sewer (Level 4)
   2. Sewage treatment (Level 4)
   3. Water purification (Level 4)
   4. Manhole
7. Soap (Level 4)
8. Sterilization
9. Water supply network (Level 4)
   1. Aqueduct (Level 4)
   2. Plumbing (Level 4)
   3. Qanat (Level 4)
   4. Pumping station (Level 4)
   5. Water tower (Level 4)
   6. Well (Level 4)

Material and chemical (27 articles)

1. Abrasive (Level 4)
2. Adhesive (Level 4)
3. Ceramic (Level 4)
   1. Pottery (Level 3)
   2. Porcelain (Level 4)
   3. Kiln
4. Chemical plant (Level 4)
5. Composite material (Level 4)
6. Explosive (Level 3)
   1. Dynamite (Level 4)
   2. Fireworks (Level 4)
7. Glass (Level 3)
   1. Glassblowing
8. Lubricant
9. Natural rubber (Level 3)
10. Paper (Level 3)
    1. Papermaking
    2. Parchment (Level 4)
       1. Vellum
    3. Tissue paper
11. Papyrus (Level 4)
12. Petrochemical (Level 4)
13. Plastic (Level 3)
    1. Injection moulding
14. Wood (Level 3)
15. Woodworking (Level 4)
    1. Carpentry (Level 4)

Metallurgy (32 articles)

1. Metallurgy (Level 3)
   1. Smelting (Level 4)
   2. Blast furnace
   3. Crucible
2. Metalworking (Level 4)
   1. Anvil
   2. Bellows
   3. Bending
   4. Casting
      1. Die casting (Level 4)
      2. Lost-wax casting
      3. Sand casting
   5. Drawing
   6. Electrical discharge machining
   7. Extrusion (Level 4)
   8. Forge
   9. Forging (Level 4)
   10. Grinding
   11. Heat treating (Level 4)
   12. Laser cutting (Level 4)
   13. Machining
   14. Metal fabrication
   15. Plating
   16. Precipitation hardening
   17. Quenching
   18. Rolling (Level 4)
   19. Sheet metal
   20. Sintering
   21. Soldering (Level 4)
   22. Steelmaking (Level 4)
   23. Welding (Level 4)
3. Ore (Level 4)

Infrastructure (208 articles)

See also Arts: Architecture

Basics (2 articles)

1. Building (Level 4)
2. Infrastructure (Level 3)

Building materials (28 articles)

1. Brick (Level 4)
2. Cement (Level 4)
   1. Portland cement
3. Concrete (Level 3)
   1. Asphalt concrete
4. Lumber (Level 4)
5. Masonry (Level 3)
6. Quarry (Level 4)
7. Scaffolding (Level 4)
8. Adobe
9. Construction aggregate
10. Clapboard
11. Fire brick
12. Gypsum plaster
13. Lath
14. Mortar
15. Plaster
16. Plaster of Paris
17. Precast concrete
18. Prestressed concrete
19. Reinforced concrete
20. Roof shingle
21. Shotcrete
22. Siding
23. Stone slab
24. Concrete slab
25. Tile
26. Wattle and daub

Infrastructure by type (91 articles)

Architectural elements (20 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. Façade (Level 4)
9. Floor (Level 4)
10. Foundation (Level 4)
11. Ladder (Level 4)
12. Lighting (Level 4)
13. Pier
14. Roof (Level 4)
15. Room (Level 4)
16. Stairs (Level 4)
17. Vault
18. Wall (Level 4)
19. Window (Level 4)

Coastal infrastructure (8 articles)

1. Dock (Level 4)
   1. Dry dock
   2. Marina
2. Harbor (Level 4)
3. Lighthouse (Level 4)
4. Pier (Level 4)
5. Port (Level 4)
6. Seawall

Ceremonial buildings (2 articles)

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

Commercial buildings (2 articles)

1. Office (Level 4)
2. Warehouse (Level 4)

Mixed-use buildings (3 articles)

1. High-rise building (Level 4)
2. Skyscraper (Level 4)
3. Tower (Level 4)

Residential buildings and housing units (10 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

Rooms and spaces (18 articles)

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

Portable buildings and shelters (2 articles)

1. Tent (Level 4)
2. Yurt

Other components (8 articles)

1. Electrical wiring (Level 4)
2. Heating, ventilation, and air conditioning (Level 4)
   1. Boiler
   2. Evaporative cooler
   3. Heat exchanger
   4. Heat pump
   5. Passive cooling
   6. Windcatcher

Hydraulic infrastructure (8 articles)

1. Drainage (Level 4)
2. Dam (Level 3)
   1. Caisson
   2. List of dams and reservoirs
3. Flood control (Level 4)
   1. Flood control in the Netherlands (Level 4)
4. Levee (Level 4)
5. Reservoir (Level 4)

Transport infrastructure (10 articles)

1. Bridge (Level 3)
   1. Cantilever bridge
   2. Drawbridge
   3. Flying junction
   4. Pontoon bridge
   5. Suspension bridge
   6. Viaduct
2. Stack interchange
3. Tunnel (Level 4)
   1. Undersea tunnel

Specific infrastructure (87 articles)

Dams (31 articles)

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

Bridges (50 articles)

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

Tunnels (3 articles)

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

Multi-modal crossings (3 articles)

1. Chesapeake Bay Bridge–Tunnel
2. Hong Kong–Zhuhai–Macau Bridge
3. Øresund Bridge

Machinery and tools (218 articles)

Basics (34 articles)

1. Machine (Level 4)
   1. Mechanism
2. Crane (Level 4)
3. Engine (Level 3)
   1. Electric motor (Level 3)
   2. 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
   3. Steam engine (Level 3)
4. Robotics (Level 3)
   1. Android
   2. Automaton
   3. Robot (Level 4)
   4. Robotic arm
   5. Leg mechanism
5. Simple machine (Level 3)
   1. Inclined plane (Level 4)
   2. Lever (Level 4)
   3. Pulley (Level 4)
      1. Block and tackle
   4. Screw (Level 4)
      1. Propeller
   5. Wedge (Level 4)
   6. Wheel (Level 3)
      1. Flywheel
   7. Wheel and axle (Level 4)
6. Siphon (Level 4)
7. System (Level 4)
   1. Complex system

Components (47 articles)

1. Axle (Level 4)
2. Blade
3. Cam
4. Belt
5. Chain (Level 4)
6. 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
7. Fastener (Level 4)
   1. Nail (Level 4)
   2. Nut (Level 4)
   3. Rivet (Level 4)
   4. Screw
   5. Washer (Level 4)
8. Gear (Level 4)
9. Kinematic pair
   1. Ball joint
   2. Bearing (Level 4)
   3. Cam follower
      1. Tappet
   4. Hinge
   5. Rack and pinion
   6. Ratchet
   7. Rod end bearing
10. Linkage
    1. Clutch (Level 4)
    2. Differential
    3. Epicyclic gearing
    4. Four-bar linkage
    5. Gimbal
    6. Whippletree
11. Lock and key (Level 4)
    1. Dead bolt
    2. Disc tumbler lock
    3. Electronic lock
    4. Lever tumbler lock
    5. Pin tumbler lock
    6. Skeleton key
12. Pipe (Level 4)
    1. Gasket (Level 4)
    2. Valve (Level 4)
13. Piston
14. Spring (Level 4)

Tools (74 articles)

1. Tool (Level 2)

Artist's tools (13 articles)

1. Eraser
2. Ink (Level 4)
3. Modelling clay (Level 4)
4. Paint (Level 4)
   1. Acrylic paint
   2. Enamel paint
   3. Varnish
5. Brush (Level 4)
6. Pastel (Level 4)
7. Pencil (Level 4)
8. Pencil sharpener
9. Pigment (Level 4)
10. Pen (Level 4)

Containers (18 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. Coffin
   2. Crate
   3. Wooden box
8. Envelope
9. Intermodal container
10. Paper cup
11. Pressure vessel
12. Steel and tin cans

Hand tools (12 articles)

1. Adze
2. Axe (Level 4)
3. Chisel (Level 4)
4. Clamp (Level 4)
5. Drilling (Level 4)
6. Hammer (Level 4)
7. Plane (Level 4)
8. Pliers
9. Saw (Level 4)
10. Scissors (Level 4)
11. Screwdriver
12. Wrench

Measuring instruments (15 articles)

1. Measuring instrument (Level 4)
   1. Barometer (Level 4)
   2. Calipers (Level 4)
   3. Ruler (Level 4)
      1. Meterstick
   4. Photometer (Level 4)
   5. Spectrometer (Level 4)
      1. Optical spectrometer
   6. Thermometer (Level 4)
   7. Astrolabe
   8. Breathalyzer
   9. Calorimeter
   10. Geiger counter
   11. Speedometer
   12. Torque wrench

Agricultural tools (15 articles)

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

Hydraulics and pneumatics (12 articles)

1. Hydraulics
   1. Cylinder
   2. Hydraulic machinery
   3. Hydraulic motor
   4. Manifold
   5. Pump
2. Pneumatics
   1. Compressor
   2. Jackhammer
   3. Nail gun
   4. Rivet gun
   5. Vacuum pump

Machinery (51 articles)

Farm and garden machinery (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
11. Reaper
12. Reaper-binder
13. Seed drill
14. Swather
15. Threshing machine
16. Transplanter

Household appliances (24 articles)

1. Home appliance (Level 4)
2. Major appliance
3. Air conditioning (Level 4)
4. Barbecue grill
5. Bidet
6. Clothes dryer (Level 4)
7. Dishwasher (Level 4)
8. Furnace (Level 4)
9. Griddle
10. Ironing (Level 4)
11. Microwave oven (Level 4)
12. Oven (Level 4)
13. Refrigerator (Level 4)
14. Sewing machine (Level 4)
15. Sink (Level 4)
16. Stove (Level 3)
    1. Electric stove
17. Toilet (Level 4)
    1. Flush toilet
    2. Squat toilet
    3. Toilet seat
    4. Urinal
18. Vacuum cleaner (Level 4)
19. Washing machine (Level 4)

Industrial machinery (11 articles)

1. Centrifuge (Level 4)
   1. Ultracentrifuge
2. Grinding mill
3. Loom (Level 4)
4. Machine tool
   1. Lathe (Level 4)
   2. Machine press (Level 4)
   3. Machining mill
   4. Numerical control
5. Potter's wheel (Level 4)
6. Spinning jenny

Media and communication (87 articles)

See also Arts: Literature; Society: Mass media; and Technology: Computing and information technology

1. Broadcasting (Level 3)
2. Communications satellite (Level 4)
3. 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
4. Ebook
   1. E-reader
5. Image (Level 4)
6. Image scanner (Level 4)
7. Mail (Level 3)
   1. Courier (Level 4)
   2. Postage stamp (Level 4)
   3. Pigeon post
8. Online dating service
9. Portable media player
   1. iPod
10. Printing (Level 3)
    1. Book (Level 2)
    2. Photocopier (Level 4)
    3. Printer (Level 4)
    4. Printing press (Level 4)
       1. Font
       2. Movable type
11. QR code
12. Radio (Level 3)
    1. Amateur radio (Level 4)
    2. Radio broadcasting (Level 4)
13. Social media (Level 4)
    1. Blog
14. Sound recording and reproduction (Level 4)
    1. Cassette tape
    2. Speaker (audio equipment) (Level 4)
    3. Phonograph
       1. Phonograph record
    4. Headphones
    5. Microphone (Level 4)
15. Speech synthesis (Level 4)
16. Telecommunications (Level 3)
    1. Modulation (Level 4)
    2. Telegraphy (Level 4)
       1. Electrical telegraph
       2. Flag semaphore
    3. Telephony
       1. Telephone (Level 3)
       2. Mobile phone (Level 3)
       3. Smartphone (Level 4)
          1. iPhone
    4. Text messaging (Level 4)
    5. Videotelephony
17. 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. Digital Video Broadcasting
       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
18. Typewriter (Level 4)
    1. QWERTY
19. Video (Level 3)
    1. Video camera (Level 4)
    2. Videocassette recorder
       1. VHS
       2. Betamax
20. Optical disc (Level 4)
    1. CD
    2. DVD
    3. LaserDisc
    4. HD DVD
    5. Blu-ray
21. Digital video recorder

Medical technology (17 articles)

Diagnostic technologies (4 articles)

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

Imaging (6 articles)

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

Devices (3 articles)

1. Artificial organ (Level 4)
2. Prosthesis (Level 4)
3. Wheelchair (Level 4)

Techniques (2 articles)

1. Cardiopulmonary bypass (Level 4)
2. Dialysis (Level 4)

Transport (2 articles)

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

Military technology (181 articles)

General (8 articles)

1. Weapon (Level 3)
2. Tank (Level 4)
3. Military technology (Level 4)
4. Horses in warfare (Level 4)
   1. Chariot (Level 4)
5. Stealth technology (Level 4)
6. War elephant (Level 4)
7. Pepper spray

Ammunition (7 articles)

1. Ammunition (Level 4)
2. Gunpowder (Level 3)
3. Bullet
4. Cartridge
   1. 9×19mm Parabellum
   2. 5.56×45mm NATO
5. Magazine

Armour (9 articles)

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

Explosive weapons (8 articles)

1. Bomb (Level 4)
2. Cluster munition (Level 4)
3. Improvised explosive device (Level 4)
4. Grenade (Level 4)
   1. Rocket-propelled grenade
5. Land mine (Level 4)
6. Missile (Level 4)
   1. Intercontinental ballistic missile

Fortification (11 articles)

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

Incendiary weapons (3 articles)

1. Greek fire
2. Napalm (Level 4)
3. Flamethrower

Melee weapons (28 articles)

1. Melee weapon
2. Battle axe (Level 4)
3. Bayonet (Level 4)
4. Brass knuckles
5. Club (Level 4)
   1. Baton
6. Mace
7. Spear (Level 4)
   1. Javelin

Knives (8 articles)

1. Knife (Level 3)
2. Dagger (Level 4)
3. Fighting knife
   1. Bowie knife
4. Hunting knife
5. Pocketknife
   1. Swiss Army knife
6. Throwing knife

Swords (11 articles)

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

Military aviation (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
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 (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 Grumman B-2 Spirit
17. Panavia Tornado
18. Rockwell B-1 Lancer

Naval warfare (15 articles)

1. Aircraft carrier (Level 4)
2. Battleship (Level 4)
3. Corvette
4. Cruiser
5. Destroyer
6. Dreadnought
7. Frigate
8. Galleon
9. Galley (Level 4)
10. Ironclad warship
11. Naval mine (Level 4)
12. Ship of the line (Level 4)
13. Submarine (Level 4)
14. Torpedo (Level 4)
15. Warship (Level 4)

Projectile weapons (30 articles)

Firearms (19 articles)

1. Firearm (Level 3)
   1. Gun
2. Handgun (Level 4)
   1. Revolver
   2. Pistol
3. Long gun
   1. Musket (Level 4)
   2. Rifle (Level 4)
      1. Assault rifle (Level 4)
      2. Sniper rifle
   3. Shotgun (Level 4)
   4. Submachine gun
4. Gatling gun
5. Machine gun (Level 4)
6. M134 Minigun
7. Automatic firearm
8. Semi-automatic firearm
9. Selective fire
10. Burst mode

Other (4 articles)

1. Boomerang (Level 4)
2. Bow and arrow (Level 3)
3. Crossbow (Level 4)
4. Sling (Level 4)

Specific firearms (7 articles)

1. AK-47
2. AR-15 style rifle
3. Glock
4. IWI Tavor
5. M4 carbine
6. M16 rifle
7. M1911 pistol

Artillery and siege (9 articles)

1. Artillery (Level 4)
2. Ballista (Level 4)
3. Battering ram (Level 4)
4. Cannon (Level 4)
5. Catapult (Level 4)
   1. Trebuchet
6. Howitzer
7. Mortar (Level 4)
8. Siege engine

Weapon of mass destruction (8 articles)

1. Weapon of mass destruction (Level 4)
2. Biological warfare (Level 4)
   1. Entomological warfare
3. Chemical weapon (Level 4)
4. Nuclear weapon (Level 3)
   1. Thermonuclear weapon (Level 4)
   2. Nuclear weapon design
   3. Nuclear proliferation

Navigation and timekeeping (66 articles)

For units of time (hour, day, etc.), see Physical sciences – Measurement. For maps, see Geography – Physical geography.

1. Calendar (Level 3)
   1. Solar calendar
      1. Gregorian calendar (Level 4)
         1. January
         2. February
         3. March
         4. April
         5. May
         6. June
         7. July
         8. August
         9. September
         10. October
         11. November
         12. December
      2. Julian calendar (Level 4)
   2. Lunisolar calendar
      1. Chinese calendar (Level 4)
   3. Lunar calendar
      1. Hebrew calendar
      2. Islamic calendar (Level 4)
   4. Leap year (Level 4)
   5. Names of the days of the week
      1. Sunday
      2. Monday
      3. Tuesday
      4. Wednesday
      5. Thursday
      6. Friday
      7. Saturday
2. Clock (Level 3)
   1. Alarm clock
   2. Atomic clock (Level 4)
   3. Digital clock
   4. Clock face
   5. Hourglass
   6. Pendulum clock
      1. Pendulum (Level 4)
   7. Quartz clock
   8. Sundial (Level 4)
   9. Watch (Level 4)
      1. Pocket watch
      2. Stopwatch
      3. Watchmaker
   10. Water clock
3. Horology
4. Time zone (Level 4)
   1. Daylight saving time (Level 4)
5. Navigation (Level 3)
   1. Compass (Level 3)
   2. Cardinal direction (Level 4)
      1. North
      2. South
      3. East
      4. West
   3. Celestial navigation (Level 4)
      1. Sextant (Level 4)
   4. Dead reckoning (Level 4)
   5. Gyroscope (Level 4)
   6. Satellite navigation (Level 4)
      1. BeiDou
      2. Galileo
      3. Global Positioning System (Level 4)
      4. GLONASS
   7. Radar (Level 3)
   8. Sonar (Level 4)

Optical technology (35 articles)

Basics (4 articles)

1. Laser (Level 3)
2. Holography (Level 4)
3. Optical fiber (Level 4)
4. Diffraction-limited system

Optics (8 articles)

1. Lens (Level 3)
   1. Fresnel lens (Level 4)
   2. Thin lens
2. Anti-reflective coating (Level 4)
3. Diffraction grating (Level 4)
4. Mirror (Level 4)
5. Polarizer (Level 4)
6. Prism (Level 4)

Optical instruments (23 articles)

1. 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)
2. Camera (Level 3)
   1. 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
      7. Flash
      8. Multi-exposure HDR capture
      9. Digital single-lens reflex camera
   2. Photographic film (Level 4)
3. Glasses (Level 4)
4. Binoculars (Level 4)
5. Charge-coupled device (Level 4)
6. Interferometry (Level 4)
7. Projector

Astronomical technology (65 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
   1. X-ray astronomy detector
5. Optical telescope (Level 4)
6. Infrared telescope
7. Radio telescope (Level 4)
8. Solar telescope
9. Space telescope
10. Theodolite (Level 4)
11. Astronomical interferometer
    1. Aperture synthesis
12. Telescope mount
    1. Altazimuth mount
    2. Equatorial mount
13. Active optics
14. Adaptive optics
15. Eyepiece
16. Astronomical filter
17. Primary mirror

Space-based observatories (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
14. XMM-Newton
15. ROSAT

Ground-based observatories (23 articles)

1. Atacama Large Millimeter Array (Level 4)
2. Mauna Kea Observatories (Level 4)
   1. 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. LOFAR
17. MeerKAT
18. Square Kilometre Array
19. Thirty Meter Telescope
20. Extremely Large Telescope
21. Giant Magellan Telescope
22. Wise Observatory

Space (70 articles)

Basics (14 articles)

1. Spaceflight (Level 3)
   1. Sub-orbital spaceflight
   2. Orbital spaceflight
2. Rocket (Level 3)
   1. Launch pad (Level 4)
   2. Launch vehicle (Level 4)
   3. Rocket engine (Level 4)
3. Satellite (Level 3)
4. Space station (Level 3)
5. Astronaut (Level 4)
   1. Space suit
6. Space capsule (Level 4)
7. Space probe (Level 4)
8. Interstellar travel

Programs and launch sites (20 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. Indian Space Research Organisation
7. Israel Space Agency
8. JAXA

Private spaceflight companies (4 articles)

1. Arianespace
2. SpaceX
3. Blue Origin
4. Virgin Galactic

Crewed vehicles (11 articles)

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

Unmanned spacecraft (18 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
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 (7 articles)

1. Mars rover
   1. Perseverance
   2. Curiosity
   3. Spirit
   4. Opportunity
   5. Sojourner
2. Lunokhod 1

Textiles (42 articles)

Fabrics and fibers (27 articles)

1. Textile (Level 3)
2. Canvas (Level 4)
3. Cotton (Level 4)
   1. Chino cloth
   2. Denim
   3. Muslin
4. Felt (Level 4)
5. Flannel
6. Fiber (Level 4)
7. Fur clothing
8. Jute (Level 4)
9. Lace (Level 4)
10. Leather (Level 4)
    1. Artificial leather
    2. Suede
11. Linen (Level 4)
12. Nylon (Level 4)
13. Polyester (Level 4)
14. Silk (Level 4)
15. Thread (Level 4)
16. Wool (Level 4)
    1. Cashmere wool
    2. Tweed
17. Yarn (Level 4)

Figures fabrics (3 articles)

1. Brocade
2. Damask
3. Songket

Techniques (15 articles)

1. Basket weaving (Level 4)
2. Crochet (Level 4)
3. Dyeing (Level 4)
   1. Dye (Level 4)
4. Embroidery (Level 4)
5. Hand spinning (Level 4)
   1. Distaff
   2. Spindle
   3. Spinning wheel
6. Knitting (Level 4)
7. Macramé (Level 4)
8. Quilting (Level 4)
9. Sewing (Level 4)
10. Tapestry (Level 4)
11. Weaving (Level 4)

Transportation (367 articles)

Basics (11 articles)

1. Transport (Level 2)
   1. Public transport (Level 4)
   2. Private transport
2. Travel (Level 4)
3. Passenger
4. Freight transport (Level 4)
   1. Cargo (Level 4)
5. Passport (Level 4)
   1. Travel visa
6. Vehicle (Level 4)
   1. Motor vehicle

Ground transport (135 articles)

Road transport (92 articles)

General

1. Carpool
2. Driving (Level 4)
   1. Parking (Level 4)
      1. Parking lot
      2. Park and ride
3. Road (Level 3)
   1. Bicycle boulevard
   2. Byway
   3. Dirt road
   4. Highway (Level 4)
      1. Controlled-access highway (Level 4)
      2. Autobahn
      3. Interstate Highway System
   5. Road junction
      1. Interchange
      2. Intersection
         1. Pedestrian crossing
         2. Traffic light
         3. Traffic sign
   6. Sidewalk
   7. Toll road
   8. Trail (Level 4)
4. Charging station
5. Filling station (Level 4)
6. Tire (Level 4)
7. Traffic collision (Level 4)

Types of road transportation

1. Bicycle (Level 3)
   1. Cycling (Level 4)
   2. Cycling infrastructure
      1. Bicycle lane
      2. Bicycle parking rack
      3. Shared-use path
      4. Bicycle-sharing system
      5. Cycle track
   3. BMX bike
   4. Electric bicycle
   5. Mountain bike
   6. Recumbent bicycle
   7. Tandem bicycle
   8. Tricycle
   9. Unicycle
2. Bus (Level 4)
   1. Articulated bus
   2. Bus rapid transit
   3. Coach
   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. Muscle car
   9. Sedan
   10. Sports car
   11. Station wagon
   12. Supercar
   13. T-top
4. Gas-guzzler
5. Hybrid vehicle
6. Motorcycle (Level 4)
   1. Chopper
   2. Minibike
   3. Moped
   4. Rat bike
   5. Scooter
      1. Kick scooter
      2. Motorized scooter
      3. Scooter-sharing system
   6. Sport bike
7. Off-road vehicle
   1. All-terrain vehicle
   2. Dune buggy
   3. Snowmobile
8. Truck (Level 4)
   1. Flatbed truck
   2. Monster truck
   3. Pickup truck
   4. Semi-trailer truck
   5. Sport utility vehicle
9. Van (Level 4)
   1. Minivan
10. Vehicle for hire
    1. Motorcycle taxi
    2. Share taxi
    3. Taxi (Level 4)

Rail transport (23 articles)

1. Rail transport (Level 3)
2. Railway electrification system
3. Track (Level 4)
4. Train (Level 4)
   1. Locomotive (Level 4)
      1. Electric locomotive
      2. Diesel locomotive
      3. Steam locomotive (Level 4)
   2. Railroad car
   3. Rolling stock
   4. Train station (Level 4)
      1. Railway platform
   5. Passenger train
   6. Rail freight transport
5. Cable car
6. Commuter rail
7. Elevated railway
8. Funicular
9. High-speed rail (Level 4)
10. Light rail
11. Monorail (Level 4)
12. Rapid transit (Level 4)
13. Tram (Level 4)

Animal-powered transport (6 articles)

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

Other (14 articles)

1. Footpath
2. Baby transport (Level 4)
3. Cable transport (Level 4)
   1. Aerial tramway (Level 4)
   2. Gondola lift
   3. Ski lift
4. Pipeline transport (Level 4)
5. Rickshaw (Level 4)
   1. Auto rickshaw
6. Heavy equipment
   1. Bulldozer
   2. Dump truck
   3. Excavator
   4. Tractor (Level 4)

Naval transport (48 articles)

For military watercraft, see Military technology

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

Aviation (85 articles)

1. Aircraft (Level 3)
2. Aircraft flight control system
3. Aircraft pilot
4. Aviation (Level 4)
5. Air traffic control (Level 4)
6. Aircraft engine (Level 4)
   1. Jet engine (Level 3)
      1. Turbofan
      2. Turbojet
   2. Turboprop
7. Airfoil
8. Airframe
9. Airline (Level 4)
10. Airplane (Level 4)
11. Airport (Level 4)
12. Aerostat
    1. Balloon (Level 4)
       1. Hot air balloon (Level 4)
       2. Gas balloon
    2. Airship (Level 4)
       1. Blimp
       2. Rigid airship
       3. Semi-rigid airship
13. Cargo aircraft
14. Fixed-wing aircraft (Level 4)
15. Flight (Level 4)
16. Flight attendant
17. Fuselage
18. General aviation
19. Glider (Level 4)
    1. Hang gliding
    2. Paragliding
20. Helicopter (Level 4)
21. Jet aircraft (Level 4)
22. Parachute (Level 4)
23. Ultralight aviation
    1. Powered paragliding
24. Unmanned aerial vehicle (Level 4)
25. Wing (Level 4)
26. Wingsuit flying

Specific aircraft (32 articles)

For military aircraft, see Military technology

1. Airbus A300
2. Airbus A320 family
3. Airbus A330
4. Airbus A340
5. Airbus A350
6. Airbus A380
7. Antonov An-225 Mriya
8. Boeing 707
9. Boeing 727
10. Boeing 737
11. Boeing 747
12. Boeing 757
13. Boeing 767
14. Boeing 777
15. Boeing 787 Dreamliner
16. De Havilland Canada Dash 8
17. Cessna 172
18. Concorde
19. de Havilland Comet
20. Douglas DC-3
21. Douglas DC-6
22. Douglas DC-8
23. Embraer E-Jet family
24. Hughes H-4 Hercules
25. Ilyushin Il-76
26. Lockheed Constellation
27. Lockheed L-1011 TriStar
28. McDonnell Douglas DC-9
29. McDonnell Douglas DC-10
30. Mil Mi-8
31. Tupolev Tu-154
32. Wright Flyer

Airports (13 articles)

1. Hartsfield–Jackson Atlanta International Airport
2. Beijing Capital International Airport
3. O'Hare International Airport
4. Dubai International Airport
5. Hong Kong International Airport
6. Heathrow Airport
7. Los Angeles International Airport
8. Charles de Gaulle Airport
9. Haneda Airport
10. Shanghai Pudong International Airport
11. Sheremetyevo International Airport
12. Indira Gandhi International Airport
13. John F. Kennedy International Airport

Individual transportation systems (88 articles)

Rapid transit (69 articles)

Africa (1 article)

1. Cairo Metro

Americas (13 articles)

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

Brazil (2 articles)

1. Rio de Janeiro Metro
2. São Paulo Metro

Canada (3 articles)

1. Montreal Metro
2. Toronto subway
3. SkyTrain

United States (5 articles)

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

Asia (29 articles)

1. Dubai Metro
2. TransJakarta
3. Mass Rapid Transit
4. Taipei Metro
5. Tehran Metro

China (9 articles)

1. Beijing Subway
2. Chongqing Rail Transit
3. Guangzhou Metro
4. MTR
5. Nanjing Metro
6. Shanghai Metro
7. Shenzhen Metro
8. Tianjin Metro
9. Wuhan Metro

India (5 articles)

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

Japan (8 articles)

1. Fukuoka City Subway
2. Kyoto Municipal Subway
3. Nagoya Municipal Subway
4. Osaka Metro
5. Sapporo Municipal Subway
6. Tokyo Metropolitan Bureau of Transportation
7. Tokyo Metro
8. Yokohama Municipal Subway

South Korea (2 articles)

1. Busan Metro
2. Seoul Metropolitan Subway

Europe (25 articles)

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

France (2 articles)

1. Lyon Metro
2. Paris Métro

Germany (2 articles)

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

Italy (2 articles)

1. Milan Metro
2. Rome Metro

Netherlands (2 articles)

1. Amsterdam Metro
2. Rotterdam Metro

Russia (2 articles)

1. Moscow Metro
2. Saint Petersburg Metro

Scandinavia (4 articles)

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

Spain (2 articles)

1. Barcelona Metro
2. Madrid Metro

United Kingdom (2 articles)

1. Glasgow Subway
2. London Underground (Level 4)

Oceania (1 article)

1. Sydney Metro

High-speed rail (13 articles)

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

Railway lines (4 articles)

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

Railway services (2 articles)

1. Indian Pacific
2. Orient Express