Technology

Camcorder — portable video camera with integrated recorder Camcorder A camcorder is a self-contained portable device that captures and records moving images. This article explains its parts, evolution, typical uses, and how it differs from other vid…

Camera: principles, components, history and common types Camera An overview of cameras: how they form images, main parts (lens, aperture, shutter, film/sensor), historical development from camera obscura to digital, and common types and uses.

Camera lens: design, types, history, and practical uses Camera lens Overview of camera lenses: how they form images, main components and optical principles, common types and uses, historical development, accessories, and practical advice for photog…

Camera obscura — the "dark chamber" optical device and its history Camera obscura A camera obscura is a light-tight space with a small aperture that projects an external scene onto an interior surface. It illustrates fundamental optical principles and influenced…

Candle: composition, burning process, history, uses and safety Candle An overview of candles: materials and construction, how they burn, historical development, common uses (lighting, scent, insect control) and safety considerations.

Capacitance Electronic Disc (CED) Capacitance Electronic Disc An analog video disc format developed by RCA that stored television-quality video and audio in grooves read by a conductive stylus; notable for its protective plastic caddy and 198…

Capacitor: function, construction, history, types and common uses Capacitor A capacitor is an electrical component that stores energy in an electric field. This article explains how capacitors work, common constructions and types, history, applications, sp…

Caps Lock key Caps lock Explanation of the Caps Lock key: function, behavior, history, differences from shift/shift-lock, practical uses, accessibility and configuration across keyboards and operating sys…

CAPTCHA: automated tests distinguishing humans from computers CAPTCHA CAPTCHA are challenges designed to tell humans and automated programs apart. This article explains how they work, common types, history, uses, accessibility concerns, and evolving…

Carbon copy (cc): paper duplicates and the legacy in modern messaging Carbon copy A carbon copy originally described a duplicate made with carbon paper placed between sheets; its abbreviation “cc” survives in mail and email to indicate additional recipients.

Carbon paper: history, composition, uses, and practical notes Carbon paper Carbon paper is a coated sheet used to create pressure-made copies. Once common for forms, receipts and typewritten duplicates, it has particular composition, limits and modern alt…

Cardboard: material, development, uses, and environmental considerations Cardboard Cardboard is a stiff paper-based material widely used for packaging, display, and craft. This article explains its structure, history, common applications, recycling, and notable d…

Carriage Return (CR): control character that resets the line position Carriage return Carriage return (CR) is a control character that returns the print head or cursor to the start of a line. It appears in text encodings, legacy devices, and modern computing line-en…

Cartoon Network Speedway: 2003 Game Boy Advance Kart Racing Game Cartoon Network Speedway A 2003 kart-racing title for the Game Boy Advance featuring Cartoon Network characters and themed tracks. Compact single-player modes, local link-cable multiplayer, and license-dri…

Cartridge: meanings, types, history, and uses Cartridge A cartridge is a removable or self-contained unit used across technologies—firearms, printers, media, audio and electronics—designed for easy replacement, interchangeability, prote…

Cartridge (electronics) A removable module or replaceable supply used in electronic devices to add functionality, store data, or refill consumables; examples include video game and printer cartridges.

Cash register (till): purpose, components, history and modern uses Cash register Device used in retail and hospitality to record sales and hold cash. Covers parts, history, security features, types (mechanical, electronic, POS) and modern cloud/mobile developme…

Cassette A cassette is a compact, self-contained container used to hold media, mechanical parts, or genetic elements. Common forms include audio and video tapes, photographic film cassettes…

Cassette player A cassette player is an electronic device that plays—and often records—audio on magnetic compact cassettes. Popular from the 1960s through the 1990s, it shaped portable listening,…

Catalytic converter A catalytic converter is an emissions-control device fitted to vehicle exhausts that uses precious metal catalysts to transform harmful gases into less harmful products; it shaped…

Cathode ray: stream of electrons and the basis of cathode ray tubes Cathode ray Cathode rays are streams of electrons emitted from a cathode in vacuum tubes. They underpinned discoveries of the electron and powered cathode ray tubes used in displays, oscillosc…

Cathode Ray Tube (CRT): design, operation, history and legacy Cathode ray tube Overview of the cathode ray tube: how CRTs work, their components and types, historical development, common uses in TVs and monitors, and reasons for their decline and environmenta…

Cavity magnetron A compact high-power vacuum tube that generates microwaves by converting electron motion into resonant cavity oscillations; key to WWII centimetre-wave radar and later microwave ov…

CD-i (Compact Disc Interactive) CD-i CD-i (Compact Disc Interactive) is a multimedia CD-based format and consumer player platform developed by Philips for interactive audio, video and software — notable for early CD-b…

CD-R (Compact Disc Recordable) CD-R CD-R is a record-once optical disc format used for music, data and mixed media. This article explains its construction, dye types, capacity, uses, compatibility and factors affecti…

CD-RW (Compact Disc ReWritable): technology, history, uses and limitations CD-RW CD-RW is a rewritable optical disc format that stores data or audio using phase-change technology. Introduced in the late 1990s, it enabled multiple recordings but had compatibilit…

CentOS — community rebuild of Red Hat Enterprise Linux CentOS CentOS is a community-driven Linux distribution historically rebuilt from Red Hat Enterprise Linux sources. Known for stability and long support cycles, it evolved into CentOS Stre…

Central Processing Unit (CPU) — Overview, Architecture, and Uses Central processing unit A central processing unit (CPU) executes instructions that run software. This article describes CPU functions, internal parts, historical development, performance measures, typical…

Centrifuge A centrifuge is a rotating device that separates components of a mixture by applying strong radial acceleration; used in laboratories, industry, medicine and isotope enrichment.

Cessna 172 (Skyhawk) — four-seat single-engine light aircraft Cessna 172 The Cessna 172 Skyhawk is a four-seat, high-wing, single-engine light airplane introduced in the 1950s. Widely used for training and private flying, it is one of the best-selling a…

Chainsaw — portable mechanical saw: design, history, uses, and safety Chainsaw Overview of chainsaws: what they are, how they work, main components, history, common uses and variations, plus maintenance and safety practices for professional and recreational u…

Character (computing) A computing character is a textual or control symbol represented by a numeric code. This article explains characters, glyphs, code points, encodings (ASCII, Unicode, UTF-8), contro…

Cheating in Video Games An overview of cheating in video games: methods, history, motivations, effects, and how developers and communities detect and respond to unfair play.

Chisel: Tools for Shaping Wood, Stone, and Metal Chisel A chisel is a hand tool with a sharpened blade used to cut, pare, or shape material. This article describes types, parts, history, common uses, maintenance, and safety.

Chroma key (green/blue screen compositing) Chroma key Chroma key is a visual-effects technique that replaces a single-color background (commonly green or blue) with a different image or video; used in film, TV, streaming and virtual p…

Chromebook — cloud-centric laptops running Chrome OS Chromebook Chromebooks are laptops that run Chrome OS, prioritize web apps and cloud storage, and are designed for speed, security and simplicity. They are widely used in education and for li…

Chromium (open-source web browser project) Chromium (web browser) Open-source browser project that provides the core code used by Google Chrome and many other browsers; a minimal, buildable upstream that omits certain proprietary components.

CIH (Chernobyl / Spacefiller) — destructive Windows 9x computer virus CIH CIH, also called Chernobyl or Spacefiller, is a 1998 Windows 9x malware known for corrupting files and, on vulnerable PCs, overwriting BIOS firmware; it prompted major data-loss in…

Circuit breaker (electrical) Circuit breaker A circuit breaker is a resettable electrical safety device that interrupts current flow on overloads or faults. This article explains its parts, operation, history, uses, and how i…

Civilization (video game series) Civilization (series) A long-running turn-based 4X strategy series created by Sid Meier. Players guide a society from ancient times to the future through city-building, research, diplomacy and warfare.

Clamp: tools and devices for holding objects firmly together Clamp A clamp is a device that holds objects securely to prevent movement or separation. Used in woodworking, metalworking, medicine and manufacturing, clamps vary widely in design and f…

Clash Royale — mobile real-time strategy and card-battle game Clash Royale Clash Royale is a freemium mobile real-time strategy game by Supercell combining collectible cards, tower defense and MOBA elements; launched in 2016 and notable for rapid revenue…

Classic Controller (Nintendo Wii) Classic Controller Wired controller that connects to the Wii Remote to provide a traditional gamepad layout for the Wii's Virtual Console, WiiWare and compatible titles.

Clipboard (computing): temporary storage for copy and paste Clipboard (computing) A system facility that temporarily holds copied data for transfer between applications, supporting multiple formats, clipboard managers, and platform-specific behaviors.

Cloaking device (invisibility cloak): science, history and applications Cloaking device An overview of cloaking devices and invisibility cloaks: physical principles, experimental milestones, common approaches and practical limits, from fiction to laboratory demonstrat…

Clock: Devices for Measuring and Displaying Time Clock Overview of clocks: how they work, main types (mechanical, quartz, atomic, digital), parts and features, history from sundials to atomic time, and uses in daily life and science.

Clock rate (processor frequency) Clock rate Clock rate describes the frequency at which a synchronous digital circuit or CPU toggles its clock signal, measured in cycles per second. It affects but does not fully determine re…

Clockwork: mechanical movements, mainsprings and gear-driven mechanisms Clockwork Clockwork denotes mechanical movements driven by a wound mainspring and gear trains. This article explains parts, history, common uses (clocks, watches, toys, automata) and how clo…