Technology

UNetbootin — Universal Netboot Installer UNetbootin UNetbootin is a utility for creating bootable Live USB drives and installing many Linux distributions and utilities without a CD, available for Windows, macOS and Linux.

Unicode: a universal standard for encoding text and symbols Unicode Overview of the Unicode standard: code points, encodings (UTF-8/UTF-16), text processing features, history, uses, and practical issues like normalization, bidi, emoji and control c…

Uninterruptible power supply (UPS): purpose, types, batteries and uses Uninterruptible power supply A UPS provides immediate backup power and power conditioning when mains supply fails. This article explains function, types, batteries, applications, sizing, maintenance and distin…

Unity (game engine): overview, features, history and uses Unity (game engine) Unity is a cross-platform game engine and development environment used for 2D, 3D, AR/VR, and simulations. It emphasizes accessibility, a large ecosystem, and rapid development wit…

Universal Media Disc (UMD) — Sony's optical format for the PSP Universal Media Disc Universal Media Disc (UMD) is Sony's proprietary optical disc for the PlayStation Portable, holding up to 900 MB (single layer) or 1.8 GB (dual layer) and used for games, music and…

UNIX: history, design, and influence UNIX UNIX is a family of multitasking, multiuser operating system concepts originating at Bell Labs. This article covers its origins, architecture, interfaces, variants, standards, and…

Unix shell: command interpreter and scripting environment Unix shell A Unix shell is the command-line interpreter for Unix-like systems, providing interactive control, scripting, pipelines, redirection, job control, and an extensible environment for…

Unix time (POSIX epoch time) Unix time Unix time counts whole seconds since the epoch (1970-01-01 00:00:00 UTC). It is a simple, widely used timestamping convention in Unix-like systems, programming, and network protoco…

Urinal deodorizer block: purpose, composition, history, and safety Urinal deodorizer block Small scented blocks placed in urinals to control odor and microbial growth; includes types, how they work, maintenance, environmental and health considerations, and alternatives.

Usability: principles, evaluation, and practical importance Usability Usability refers to how easily people can use a product, system, or service to achieve goals. This article explains core attributes, evaluation methods, history, applications, and…

Universal Serial Bus (USB): Overview, Connectors, History and Uses USB An accessible overview of the Universal Serial Bus (USB): its purpose, architecture, connector types, data-rate generations, power delivery, common uses, compatibility and recent d…

USB flash drive Small, removable storage device using flash memory and a Universal Serial Bus interface; used for file transfer, backups, bootable systems and portable applications.

USB hub: functions, types, power and performance USB hub A USB hub expands USB ports, manages power and data for multiple devices, and mediates speed and compatibility across USB standards and topologies.

User (computing) A computing user is an identity or account that interacts with a computer or network service; covers accounts, authentication, authorization, types, history and security practices.

User interface: types, design principles, and safety considerations User interface A concise, neutral overview of user interfaces: definitions, common types, key design principles, accessibility and safety issues, with examples and brief history.

Utility pole A utility pole is a freestanding structure used to support electrical conductors, communications lines and related equipment; typically made of wood, steel, concrete or composites.

Utility software (system utilities) Utility software Utility software consists of general-purpose programs that perform maintenance, management, security, and diagnostic tasks for computers and devices, distinct from application soft…

V-Rally 2 V-Rally 2 is a rally racing game from the late 1990s. Developed by Eden Studios and published by Infogrames, it appeared on PlayStation, Dreamcast and PC under several regional tit…

V.Flash (V.Smile Pro) — VTech 3D educational home console V.Flash The V.Flash (marketed in Europe as V.Smile Pro) is VTech's 2006 3D educational home video game console for children aged five and up, combining gameplay with curriculum‑based learn…

Vacuum cleaner: function, types, history, and maintenance Vacuum cleaner Comprehensive guide to vacuum cleaners: how they work, common types, historical development, applications, maintenance tips, and environmental or allergen considerations.

Value (computer science) A value is a discrete piece of information manipulated by programs — e.g., numbers, strings, booleans, objects — distinct from variables or storage that may refer to it.

Vampire tap (coaxial network connector) Vampire tap A vampire tap is a clamp-style connector that pierces a coaxial cable's shield to contact the center conductor, used historically to attach devices to 10BASE5 Ethernet 'Thicknet' b…

Van de Graaff generator — electrostatic high-voltage generator Van de Graaff Generator Electrostatic device that uses a moving insulating belt to concentrate charge on a hollow metal sphere, producing very high voltages for research, accelerators, industry and classr…

Variable-width encoding: principles, examples, and trade-offs Variable-width encoding An overview of variable-width character encodings: how they work, common forms (UTF-8, UTF-16), benefits and drawbacks, historical context, and practical implications for software…

Varistor (Voltage-Dependent Resistor): Function, Types, and Uses Varistor A varistor is a non-linear resistor used to suppress voltage transients. This article explains how it works, construction and types, typical applications, history, comparisons and…

vCard — The Electronic Business Card Format VCard vCard is a standardized, text-based format for exchanging contact information (commonly .vcf) used in email, devices, QR codes and contact-management systems.

Vector graphics editor Software for creating and editing images defined by mathematical shapes. Produces scalable artwork using paths, fills and strokes and exports to formats such as SVG, PDF and EPS.

Vectrex: the Vector-Display Home Video Game Console Vectrex Early 1980s self-contained home console built around a monochrome vector CRT. Noted for sharp wireframe graphics, plastic color overlays, unusual accessories and a small devoted so…

VEGAS Pro — professional non-linear video editing software VEGAS Pro VEGAS Pro is a Windows-only non-linear video editor noted for a timeline-focused workflow, integrated audio tools, and a long development history from Sonic Foundry to MAGIX.

Vending machine: automated retail devices — types, history, and uses Vending machine Automated retail devices that dispense goods or services for payment. Overview of operation, typical products, historical development, modern features and notable regional uses.

Ventilator (mechanical breathing support) Ventilator A ventilator is a medical device that assists or replaces spontaneous breathing. This article explains how ventilators work, their types and modes, components, history, clinical us…

VDSL (Very High Bitrate Digital Subscriber Line): high-speed copper broadband technology Very High Bitrate Digital Subscriber Line VDSL (Very High Bitrate DSL) is a high-speed broadband technology using existing copper phone lines to deliver data, voice and TV; VDSL2 can reach up to ~100 Mbps over short distan…

Very Long Instruction Word (VLIW) computer architecture Very long instruction word VLIW is a processor architecture that encodes multiple operations into a single wide instruction word so a simple core can execute them in parallel based on compile-time scheduling…

VGA connector — analog video interface (DE-15) VGA connector VGA connector: a common 15-pin D-sub analog video plug used to carry RGB and sync signals between computers and displays; legacy standard with widespread adapter options and simple…

VHS (Video Home System): overview, history, and legacy VHS VHS (Video Home System) is an analog videocassette format introduced in the 1970s that dominated home video recording and playback through the 1980s–1990s before being superseded b…

Vibrator A vibrator is any device or component that produces mechanical vibration, including personal massagers, industrial machines, historic electronic parts, and instruments that use vib…

Vibrator (sensual device) Vibrator (sensual) A vibrator is a device that produces vibrations against the body to provide sexual or therapeutic stimulation. Available in many shapes, materials and power sources, it is used sol…

Video camera: principles, history, components, and uses Video camera Comprehensive overview of video cameras: how they capture moving images and sound, main components, historical development from analog to digital, common applications, and current…

Video card (graphics card): function, components, history and uses Video card A video card (graphics card) is hardware that renders 2D and 3D images, controls display outputs and accelerates graphics and parallel compute tasks for games, design, media and sc…

Video CD (VCD): digital movie format on compact disc Video CD Overview of the Video CD (VCD) format: how it stores video and audio on compact discs, its technical limits, history, typical uses, and how it compares to DVD and VHS.

Video game console: overview, types, components, history and uses Video game console An overview of video game consoles: their hardware, categories (home, handheld, hybrid), controllers, evolution, cultural impact, and examples, with links to related topics and sof…

Video Game Content Rating System Systems used to evaluate and label video game content for age-appropriateness, provide content descriptors, and guide consumers, parents, retailers, and policy makers.

Video Game Developer: Roles, Types, and the Game-Making Process Video game developer Comprehensive overview of video game developers: what they do, team roles, studios vs indie creators, platforms, development stages, business models, history and current trends.

Video Game Producer — Role, History, Responsibilities and Career Video game producer An overview of the video game producer: duties, types, origin, career path and how the role shapes game development.

Video projector: technology, types, uses, and key features Video projector Overview of video projectors, how they work, main technologies, common features and uses from classroom and conference rooms to home theater and large venues.

Videocassette recorder (VCR): history, technology, and cultural impact Videocassette recorder Overview of the videocassette recorder (VCR): how it works, key components and formats, historical development, common uses like time‑shifting, and its legacy after the rise of dig…

Videotape: magnetic recording medium for moving images and sound Videotape Videotape is a plastic-based magnetic medium used to record moving images and sound. Widely used from the 1950s through the late 20th century, it shaped broadcasting, home video an…

Vim (Vi IMproved): modal text editor — history, features, and uses Vim Vim is a modal, extensible text editor descended from vi. This article summarizes its history, core concepts (modes, motions, registers), customization, platforms, community and co…