This section contains 2 articles.

1. Agricultural science
2. Crop

This section contains 9 articles.

1. Aquaculture
2. Beekeeping
3. Dairy
4. Gardening
5. Intensive farming
6. Orchard
7. Organic farming
8. Sustainable agriculture
9. Subsistence agriculture

This section contains 6 articles.

1. Garden (Level 3)
2. Farm
3. Barn
4. Stable
5. Silo
6. Granary

This section contains 6 articles.

1. Animal husbandry (Level 3)
2. Domestication (Level 3)
3. Selective breeding
4. Breed
5. Livestock
6. Hay

This section contains 9 articles.

This section contains 4 articles.

1. Agronomy
2. Horticulture
3. Plant breeding
   1. Cultivar

This section contains 5 articles.

1. Fertilizer (Level 3)
2. Harvest
3. Irrigation
4. Pesticide
5. Tillage

This section contains 8 articles.

1. Computing
2. Information technology
3. Abacus
4. Calculator
5. Computer security
   1. Malware
6. Data
   1. Data communication

This section contains 7 articles.

1. Computer science (Level 3)
2. Artificial intelligence (Level 3)
   1. Large language model
3. Computer architecture
4. Computer simulation
5. Parallel computing
6. Pixel

This section contains 10 articles.

1. Computer hardware
2. Computer (Level 2)
   1. Mobile device
      1. Smartphone
         1. iPhone
   2. Personal computer
      1. Mac (computer)
   3. Supercomputer
3. Central processing unit
4. ENIAC

This section contains 7 articles.

1. Computer program
2. Database
3. Open-source software
4. Software
5. Spreadsheet
6. Web browser
7. Word processor

This section contains 6 articles.

1. Operating system
2. Android
3. Linux
4. Microsoft Windows
5. MS-DOS
6. Unix

This section contains 5 articles.

1. User interface
2. Computer keyboard
3. Computer monitor
4. Mouse (computing)
5. Touchscreen

This section contains 3 articles.

1. Cryptography (Level 3)
2. Authentication
3. Encryption

This section contains 11 articles.

1. Computer file
   1. File system
2. Barcode
3. Data storage
4. Hard disk drive
5. Magnetic tape
6. Memory card
7. Optical disc
8. Punched card
9. Random-access memory
10. Read-only memory

This section contains 5 articles.

1. Computer network
2. Email
3. Ethernet
4. Router
5. Wi-Fi

This section contains 7 articles.

1. Internet (Level 3)
2. HTTP
3. Internet protocol suite
4. Search engine
5. Social media
6. Website
7. World Wide Web

This section contains 13 articles.

1. Computer programming
2. Character encoding
3. Compiler
4. Programming language
   1. Assembly language
   2. C
   3. HTML
   4. Java (programming language)
   5. JavaScript
5. Programming paradigm
   1. Functional programming
   2. Structured programming
      1. Object-oriented programming

This section contains 12 articles.

1. Factory
   1. Assembly line
   2. Automation
   3. Industrial robot
   4. Interchangeable parts
   5. Mass production
   6. Mechanization
2. Standardization
3. Waste
   1. Landfill
   2. Recycling
   3. Waste management

This section contains 36 articles.

1. Fuel
   1. Candle
2. Biofuel
   1. Charcoal
3. Fossil fuel (Level 3)
   1. Coal (Level 3)
   2. Natural gas (Level 3)
   3. Petroleum (Level 3)
      1. Gasoline
      2. Kerosene
      3. Oil refinery
      4. Oil well
4. Nuclear power (Level 3)
5. Renewable energy (Level 3)
   1. Geothermal power
   2. Hydropower (Level 3)
      1. Hydroelectricity
      2. Watermill
   3. Solar energy (Level 3)
      1. Solar power
      2. Solar cell
   4. Wind power (Level 3)
      1. Windmill

This section contains 13 articles. See also: Electromagnetism and Electromagnetism

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

This section contains 18 articles.

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

This section contains 20 articles.

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

This section contains 12 articles.

1. Metallurgy (Level 3)
   1. Smelting
2. Metalworking
   1. Die casting
   2. Extrusion
   3. Forging
   4. Heat treating
   5. Laser cutting
   6. Rolling
   7. Soldering
   8. Steelmaking
   9. Welding

This section contains 2 articles.

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

This section contains 7 articles.

1. Concrete (Level 3)
2. Masonry (Level 3)
   1. Brick
   2. Quarry
3. Cement
4. Lumber
5. Scaffolding

This section contains 48 articles.

This section contains 16 articles.

1. Arch
2. Ceiling
3. Column
4. Dome
5. Door
6. Elevator
7. Façade
8. Floor
9. Foundation
10. Ladder
11. Lighting
12. Roof
13. Room
14. Stairs
15. Wall
16. Window

This section contains 5 articles.

1. Dock
2. Harbor
3. Lighthouse
4. Pier
5. Port

This section contains 2 articles.

1. Pagoda
2. Pyramid

This section contains 2 articles.

1. Office
2. Warehouse

This section contains 3 articles.

1. Tower
2. Tower block
3. Skyscraper

This section contains 3 articles.

1. Electrical wiring
2. Heating, ventilation, and air conditioning
   1. Fireplace

This section contains 10 articles.

1. Dam (Level 3)
   1. Aswan Dam
   2. Hoover Dam
   3. Itaipu Dam
   4. Three Gorges Dam
2. Drainage
3. Flood management
   1. Flood control in the Netherlands
4. Levee
5. Reservoir

This section contains 7 articles.

1. Bridge (Level 3)
   1. Akashi Kaikyo Bridge
   2. Brooklyn Bridge
   3. Golden Gate Bridge
   4. Tower Bridge
2. Tunnel
   1. Channel Tunnel

This section contains 21 articles.

1. Machine
2. Crane (machine)
3. Engine (Level 3)
   1. Electric motor (Level 3)
   2. Internal combustion engine (Level 3)
      1. Diesel engine
      2. Four-stroke engine
   3. Jet engine
   4. Steam engine (Level 3)
4. Robotics (Level 3)
   1. Robot
5. Simple machine (Level 3)
   1. Inclined plane
   2. Lever
   3. Pulley
   4. Screw mechanism
   5. Wedge
   6. Wheel (Level 3)
   7. Wheel and axle
6. Siphon
7. System

This section contains 16 articles.

1. Axle
   1. Bearing
   2. Clutch
   3. Gear
2. Electrical cable
   1. Chain
   2. Rope
3. Fastener
   1. Knot
   2. Nail (fastener)
   3. Nut (hardware)
   4. Rivet
4. Lock and key
5. Pipe
   1. Valve
6. Spring (device)

This section contains 34 articles.

This section contains 2 articles.

1. Tool (Level 2)
2. Container

This section contains 7 articles.

1. Instrumentation
   1. Barometer
   2. Calipers
   3. Photometer
   4. Ruler
   5. Spectrometer
   6. Thermometer

This section contains 8 articles.

1. Ink
2. Modelling clay
3. Paint
4. Brush
5. Pastel
6. Pencil
7. Pigment
8. Pen

This section contains 8 articles.

1. Axe
2. Chisel
3. Clamp
4. Drilling
5. Hammer
6. Plane (tool)
7. Saw
8. Scissors

This section contains 9 articles.

1. Archimedes' screw
2. Harrow (tool)
3. Hoe (tool)
4. Machete
5. Plough
6. Rake (tool)
7. Sickle
8. Shovel
9. Wheelbarrow

This section contains 26 articles.

This section contains 6 articles.

1. Chainsaw
2. Combine harvester
3. Cotton gin
4. Cultivator
5. Irrigation sprinkler
6. Lawn mower

This section contains 15 articles.

1. Home appliance
2. Air conditioning
3. Clothes dryer
4. Dishwasher
5. Furnace (central heating)
6. Ironing
7. Microwave oven
8. Oven (Level 3)
9. Refrigerator
10. Sewing machine
11. Sink
12. Stove
13. Toilet
14. Vacuum cleaner
15. Washing machine

This section contains 5 articles.

1. Centrifuge
2. Lathe
3. Loom
4. Machine press
5. Potter's wheel

This section contains 5 articles.

1. Artificial organ
2. Dentures
3. Prosthesis
4. Stethoscope
5. Wheelchair

This section contains 2 articles.

1. Bandage
2. Syringe

This section contains 1 article.

1. Cardiopulmonary bypass

This section contains 3 articles.

1. DNA profiling
2. Electrocardiography
3. Endoscopy

This section contains 1 article.

1. Ambulance

This section contains 4 articles.

1. Medical imaging (Level 3)
2. Magnetic resonance imaging
3. Medical ultrasonography
4. Radiography

This section contains 7 articles.

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

This section contains 2 articles.

1. Ammunition
2. Gunpowder (Level 3)

This section contains 6 articles.

1. Armour (Level 3)
2. Bulletproof vest
3. Helmet
4. Chain mail
5. Plate armour
6. Shield

This section contains 6 articles.

1. Bomb (Level 3)
2. Cluster munition
3. Improvised explosive device
4. Grenade
5. Land mine
6. Missile

This section contains 3 articles.

1. Fortification (Level 3)
   1. Castle
   2. Defensive wall

This section contains 1 article.

1. Napalm

This section contains 9 articles.

1. Knife (Level 3)
   1. Dagger
2. Sword
   1. Katana
   2. Rapier
3. Battle axe
4. Bayonet
5. Club (weapon)
6. Spear

This section contains 4 articles.

1. Military aircraft
2. Attack aircraft
3. Bomber
4. Fighter aircraft

This section contains 8 articles.

1. Aircraft carrier
2. Battleship
3. Galley
4. Naval mine
5. Ship of the line
6. Submarine
7. Torpedo
8. Warship

This section contains 12 articles.

1. Boomerang
2. Bow and arrow
3. Crossbow
4. Firearm (Level 3)
   1. Rifle
      1. Assault rifle
   2. Handgun
   3. Machine gun
   4. Musket
   5. Shotgun
5. Gun
6. Sling

This section contains 6 articles.

1. Artillery
2. Ballista
3. Battering ram
4. Cannon
5. Catapult
6. Mortar

This section contains 5 articles.

1. Weapon of mass destruction
2. Biological warfare
3. Chemical weapon
4. Nuclear weapon
   1. Thermonuclear weapon

This section contains 14 articles.

1. Calendar (Level 3)
   1. Chinese calendar
   2. Gregorian calendar
   3. Islamic calendar
   4. Julian calendar
   5. Leap year
2. Coordinated Universal Time
3. Clock (Level 3)
   1. Watch
   2. Atomic clock
   3. Pendulum
   4. Sundial
4. Time zone
   1. Daylight saving time

This section contains 10 articles. See the Cartography section under Geography for Map.

1. Navigation (Level 3)
   1. Compass (Level 3)
   2. Celestial navigation
      1. Sextant
   3. Dead reckoning
   4. Gyroscope
   5. Satellite navigation
      1. Global Positioning System
2. Radar (Level 3)
3. Sonar

This section contains 3 articles.

1. Laser (Level 3)
2. Holography
3. Optical fiber

This section contains 6 articles.

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

This section contains 16 articles.

1. Microscope (Level 3)
   1. Electron microscope
   2. Optical microscope
2. Telescope (Level 3)
   1. Optical telescope
   2. Radio telescope
   3. Theodolite
3. Camera (Level 3)
   1. Photography (Level 3)
      1. Digital photography
      2. Fine-art photography
   2. Photographic film
4. Glasses
5. Binoculars
6. Charge-coupled device
7. Interferometry

This section contains 10 articles.

1. Space exploration (Level 3)
   1. Exploration of Mars
2. Spaceflight (Level 3)
3. Spacecraft
4. Rocket (Level 3)
   1. Launch vehicle
   2. Rocket engine
5. Satellite (Level 3)
6. Space station (Level 3)
7. Astronaut

This section contains 9 articles.

1. NASA
   1. Apollo program
   2. Kennedy Space Center
   3. Voyager program
2. Soviet space program
   1. Baikonur Cosmodrome
3. Roscosmos
4. European Space Agency
5. China National Space Administration

This section contains 5 articles.

1. International Space Station
2. Mir
3. Space Shuttle
4. Saturn V
5. Soyuz (spacecraft)

This section contains 2 articles.

1. Hubble Space Telescope
2. Sputnik 1

This section contains 2 articles.

1. Atacama Large Millimeter Array
2. Mauna Kea Observatories

This section contains 12 articles.

1. Textile (Level 3)
2. Canvas
3. Cotton (Level 3)
4. Felt
5. Fiber
6. Lace
7. Leather
8. Linen
9. Silk
10. Thread
11. Wool
12. Yarn

This section contains 10 articles.

1. Basket weaving
2. Crochet
3. Dye
4. Embroidery
5. Hand spinning
6. Knitting
7. Quilting
8. Sewing
9. Tapestry
10. Weaving

This section contains 7 articles.

1. Transport (Level 2)
   1. Public transport
2. Travel
3. Freight transport
   1. Cargo
4. Passport
5. Vehicle

This section contains 19 articles.

1. Road transport
2. Road (Level 3)
   1. Highway
      1. Controlled-access highway
   2. Trail
3. Car (Level 3)
4. Bicycle (Level 3)
   1. Cycling
5. Bus
6. Motorcycle
7. Rickshaw
8. Truck
9. Taxi
10. Van
11. Driving
    1. Parking
12. Tire
13. Filling station
14. Traffic collision

This section contains 3 articles.

1. Carriage
2. Cart
3. Saddle

This section contains 14 articles.

1. Train (Level 3)
   1. Locomotive
      1. Steam locomotive
   2. Train station
2. Rail transport
3. Railway track
4. Rapid transit
   1. London Underground
   2. New York City Subway
5. High-speed rail
   1. Shinkansen
6. Monorail
7. Tram
8. Trans-Siberian Railway

This section contains 17 articles.

1. Aircraft (Level 3)
2. Aviation
3. Air traffic control
4. Aircraft engine
5. Airline
6. Airplane
7. Airport
8. Airship
9. Balloon (aeronautics)
   1. Hot air balloon
10. Fixed-wing aircraft
11. Glider
12. Helicopter
13. Jet aircraft
14. Parachute
15. Unmanned aerial vehicle
16. Wing

This section contains 20 articles.

1. Maritime transport
2. Ship (Level 3)
3. Canal (Level 3)
   1. Lock (water navigation)
4. Barge
5. Boat
6. Canoe
7. Cargo ship
8. Ferry
9. Fishing vessel
10. Hovercraft
11. Merchant ship
12. Passenger ship
13. Riverboat
14. Sailing
    1. Sail
15. Sailing ship
16. Shipbuilding
17. Steamship
18. Tanker

This section contains 3 articles.

1. Cable transport
2. Pipeline
3. Tractor