Technology

Dot-matrix printing: mechanism, history, uses, and legacy Dot matrix printing Comprehensive overview of dot-matrix printers: how they work, main components, development, common applications (multipart forms, industrial use), advantages, limitations and basic…

Dota 2 — Valve's multiplayer online battle arena Dota 2 Dota 2 is a team-based multiplayer online battle arena (MOBA) developed by Valve, evolved from the Warcraft III mod Defense of the Ancients; known for complex strategy and a global…

dpkg: Debian’s low-level package manager dpkg dpkg is the low-level package management tool used by Debian and its derivatives to install, remove and inspect .deb packages. It provides package operations, database maintenance,…

DragonFly BSD — a BSD operating system focused on SMP and HAMMER DragonFly BSD DragonFly BSD is an open-source Unix-like OS forked from FreeBSD in 2003, designed for scalable symmetric multiprocessing, with lightweight kernel threads and the HAMMER family of…

Sega Dreamcast: an overview of Sega's final home console Dreamcast The Dreamcast was Sega's last home video game console. Launched in the late 1990s, it introduced built‑in online play and innovative peripherals but ended production after strong c…

Dreamlinux — a Brazilian, Debian-based Linux distribution Dreamlinux Dreamlinux was a user-friendly, Debian-based Linux distribution from Brazil that provided live media, Portuguese support and a desktop-focused environment aimed at home and small-o…

Drill: types, parts, uses and history Drill A drill is a rotary tool used to bore holes, drive fasteners, or power attachments. Available as hand, corded electric, cordless battery models, and specialized variants like hamme…

Drupal — Free, open-source content management system Drupal Drupal is a modular, PHP-based content management framework used to build websites and web applications. It emphasizes flexibility, extensibility, multilingual support, and a large…

Dry plate (gelatin photographic process) Dry plate A photographic plate coated with a light-sensitive gelatin emulsion. Invented in 1871, dry plates replaced wet collodion plates and helped modernize photography by enabling pre-mad…

Dry toilet: types, function, benefits and sanitation considerations Dry toilet Dry toilets collect human excreta without using flushing water. This article outlines common types, how they work, health and environmental considerations, selection guidance and r…

DSLinux — Linux port for the Nintendo DS DSLinux DSLinux is a community port of the Linux operating system to the Nintendo DS handheld, used by hobbyists to run basic Unix tools, experiment with hardware, and learn embedded devel…

DualShock: Sony's iconic vibration controller for PlayStation DualShock The DualShock is Sony's dual-motor vibration controller introduced for the PlayStation line in the late 1990s. It combined analog sticks, pressure-sensitive buttons and force feedb…

Duck typing (programming concept) Duck typing Duck typing is a programming approach that determines suitability by an object's behavior (methods and properties) rather than its explicit type. Common in dynamic languages and in…

Duct tape: overview, construction, history and common uses Duct tape Duct tape is a strong, cloth-backed adhesive tape used for temporary repairs, crafts and sealing. This article explains its materials, origin, typical uses, limitations and cultura…

DVD (Digital Versatile Disc) — optical disc format DVD Overview of the DVD: its physical structure, capacities and formats, history and uses, and compatibility considerations for video, data and recordable discs.

DVD player A consumer electronic device that reads and plays discs formatted as DVD (Digital Versatile Disc), used for video, audio, data playback and home entertainment from the 1990s onward…

DVD region code Geographic digital-rights control on DVD releases that restricts playback by area. Covers purpose, how codes work, region assignments, ways to bypass, and relationship to other for…

DVD-Audio: high-resolution optical audio format DVD-Audio DVD-Audio is an optical disc format for high-resolution and multichannel audio, designed to exceed CD quality and support lossless compression and surround mixes; it remained a nic…

DVD-R — recordable DVD (write-once optical disc) DVD-R DVD-R is a write-once optical disc format using a dye recording layer to store video, audio or data (typically 4.7 GB). It competes with DVD+R and DVD-RAM and has a dual-layer DVD-…

Dvorak Simplified Keyboard An alternative English keyboard layout designed in the 1930s to reduce finger movement and increase comfort by placing common letters on the home row; adoption and efficiency remai…

Dvorak technique — satellite-based estimation of tropical cyclone intensity Dvorak technique A subjective, widely used satellite interpretation system developed by Vernon Dvorak (1974) to estimate tropical cyclone strength from visible and infrared imagery; basis for opera…

Dye-sublimation printer: principles, applications, and comparison to other photo printers Dye-sublimation printer Overview of dye-sublimation printing (dye‑sub): thermal transfer process, consumables, typical uses, image characteristics, benefits and limitations, and comparisons with inkjet an…

Dynamic Random-Access Memory (DRAM) Dynamic random-access memory DRAM is the dominant type of volatile semiconductor memory used for main system memory. It stores bits in capacitors and requires periodic refresh; variants include SDRAM and DDR g…

Dynamic-link library (DLL) Dynamic-link library A dynamic-link library (DLL) is Windows' shared library format that lets programs share code and resources at run-time. This article explains formats, structure, history, uses, and…

E‑book: digital books, formats, devices, and history e-book E‑books are books in digital form read on computers, tablets, phones, or dedicated e‑readers. This article covers formats, features, history, uses, and distinctions from printed an…

E-book reader — dedicated devices for reading digital books E-book reader A portable electronic device optimized for reading digital books and periodicals, using paper-like displays, long battery life and software for annotations, libraries and adjustabl…

EasyBCD — graphical tool for configuring the Windows bootloader EasyBCD EasyBCD is a user-oriented utility for editing and managing the Windows Boot Configuration Data (BCD), enabling dual- and multi-boot setups, repair, and custom boot entries.

EBCDIC (Extended Binary Coded Decimal Interchange Code) EBCDIC EBCDIC is a family of 8-bit character encodings developed by IBM for mainframes and midrange systems, derived from punched-card codes and still found in legacy environments requiri…

Editor: roles, types, history, and importance Editor A comprehensive overview of editors: definitions, principal roles, historical development, common types (text, film, photo, software), and why editing matters in publishing and med…

EDVAC — early stored‑program electronic computer EDVAC EDVAC (Electronic Discrete Variable Automatic Computer) was an early binary, stored‑program electronic computer influential in the development of modern computer architecture.

EEPROM: Electrically Erasable Programmable Read-Only Memory EEPROM EEPROM is a non-volatile memory technology that can be electrically erased and reprogrammed at the byte level; commonly used for system settings, microcontrollers, smart cards and…

Electricity meter: function, types, history and uses Electricity meter Device that records electrical energy consumption, commonly in kilowatt‑hours; covers types (mechanical, electronic, smart), operation, history, uses and notable distinctions.

Electro‑Optic Modulator: principles, types, and applications Electro-optic modulator An electro‑optic modulator (EOM) is a device that controls light by an applied electric field, altering phase, amplitude or polarization; used widely in communications, sensing and…

Electrocardiogram (ECG/EKG): recording the heart's electrical activity Electrocardiogram An electrocardiogram (ECG or EKG) records the heart's electrical activity to assess rhythm, rate, conduction, chamber effects and evidence of ischemia or damage. It is rapid, nonin…

Electron microscope: principles, types, history and applications Electron microscope An electron microscope uses focused electron beams to image structures far smaller than visible light allows. Covers operation, main types (TEM, SEM, cryo‑EM), history, uses and pr…

Electronic component Basic device used to build electronic circuits; includes passive and active parts, discrete items and integrated circuits, with roles, packaging, history, and common examples.

Electronic Delay Storage Automatic Calculator (EDSAC) Electronic Delay Storage Automatic Calculator EDSAC was an early British stored‑program computer built at Cambridge under Maurice Wilkes. It used mercury delay‑line memory, first ran programs in 1949, and influenced early comm…

Electronic signature: definition, types, history, and legal use Electronic signature An electronic signature is data in electronic form indicating consent or approval. This article explains types, technical and legal distinctions, history, common uses, and key inte…

Electronic system An electronic system uses electrical energy to manipulate signals or data. This article explains core components, typical functions, brief development history, common applications…

Electronics: Principles, Components, Systems, and Applications Electronics A concise overview of electronics: fundamentals of circuits and components, system architecture (input, processing, output), historical context, typical devices and applications, a…

Elephant gun A large-bore firearm designed historically for hunting the biggest game. Covers design features, historical development, typical cartridges and uses, plus distinctions from modern…

Elive — Debian 10-based Linux distribution with the Enlightenment desktop Elive Elive is a Debian 10 (Buster) based Linux distribution that uses the Enlightenment desktop, designed to run on both legacy and modern hardware with live and persistent USB options.

ELIZA — early natural language chatbot and psychotherapy simulation ELIZA ELIZA is a 1960s program by Joseph Weizenbaum that processed simple natural language input. Its DOCTOR script mimicked a Rogerian therapist and exposed limits of pattern-matching c…

Embedded system A specialized computing unit designed to perform dedicated control, monitoring, or processing tasks within a larger device or system.

Embraer E-Jet family: regional twinjet airliners Embraer E-Jet family A family of narrow-body, twin‑engine regional airliners built by Embraer in Brazil. E-Jets serve short- and medium-haul routes in several size variants and a second‑generation E2 u…

Emerging technologies: overview, examples, and societal impact Emerging technologies Survey of emerging technologies: what they are, defining traits, historical drivers, representative fields, common applications, and social, ethical and regulatory considerations.

Emulator (computing): overview, types, history and uses Emulator Software or hardware that reproduces the behavior of one computer system on another, enabling legacy programs, games, and different operating environments to run on modern machines…

EMV: The Chip-Based Standard for Payment Cards EMV EMV is an international standard for smart payment cards and terminals that replaced magnetic-stripe cards with chip-based cryptography to reduce fraud and enable new transaction m…