Technology

Noto — Google's multilingual font family Noto (font) Noto is a comprehensive, open-source font family by Google designed to support a wide range of scripts, symbols and emoji for consistent international typography.

NTFS (New Technology File System) NTFS NTFS is Microsoft's modern file system introduced for Windows NT. It provides journaling, security, large-volume support and features such as the Master File Table, encryption and…

nUbuntu — Ubuntu remaster for network security and penetration testing nUbuntu nUbuntu is a community remaster of Ubuntu that packages common penetration-testing tools into a Live CD and full-install desktop, aiming to combine Ubuntu usability with security t…

Numerical control (NC) and computer numerical control (CNC) Numerical control Numerical control (NC) automates machine operation by executing stored instruction sequences; its computer-driven form, CNC, enables precise, repeatable and complex machining from…

Nut (hardware) A nut is a fastener with an internally threaded hole, commonly paired with a bolt to clamp parts together. Types, materials, standards, and installation practices affect strength a…

Nutcracker: tool, types, history and cultural significance Nutcracker A nutcracker is a tool for opening hard-shelled nuts. This article explains how nutcrackers work, common designs, historical notes, culinary and cultural uses, and safety and indus…

Nylon: Synthetic Polyamide Fiber Nylon Nylon is a family of synthetic polyamides widely used for textiles and engineering plastics. Developed in the 1930s, it is prized for strength, elasticity, abrasion resistance and…

Objective-C (programming language) Objective-C Objective-C is a general-purpose, object-oriented language that extends C with dynamic runtime messaging. It has been widely used for developing macOS and iOS apps and interoperate…

Octopus card — Hong Kong contactless stored-value payment card Octopus card Octopus card is a reusable contactless stored-value smart card from Hong Kong used for public transport and small retail payments, introduced in 1997 and influential on later urban…

Original Equipment Manufacturer (OEM): definition, usage, and distinctions OEM An overview of OEM — what the term means, common contexts (automotive, electronics, computing, software), how OEM products differ from aftermarket or retail versions, and practical…

Off-site data protection (vaulting): overview, methods, and best practices Off-site data protection Off-site data protection—also called vaulting—means storing copies of critical information away from the main site. This article explains methods, history, risks, and operational b…

Office suite (software) Office suite An office suite is a collection of productivity applications bundled to handle common workplace tasks — document creation, spreadsheets, presentations, email and more — available a…

Oil platform A large maritime structure for drilling, producing and processing oil and natural gas from beneath the seabed; types, components, history, operations, and environmental considerati…

One Instruction Set Computer (OISC): Overview, Types, and Uses One instruction set computer An explanatory article on One Instruction Set Computers (OISC): the idea of a single-instruction machine, common implementations, historical notes, practical uses, and how OISCs di…

One-time pad A one-time pad is a symmetric cipher that can provide perfect secrecy when used correctly. It requires a key as long as the message, true randomness, single use, and secure key dis…

OneDrive — Microsoft cloud storage, sync, and Office integration OneDrive OneDrive is Microsoft’s cloud file storage and synchronization service. It provides web, desktop, and mobile access, Office editing in the browser, file sharing, versioning and a b…

ONS coding system: hierarchical geographic codes for UK statistics ONS coding system A neutral overview of the Office for National Statistics coding system: purpose, hierarchical structure, levels used for census and official statistics, maintenance, uses and pract…

OpenBSD: a security-focused BSD operating system OpenBSD OpenBSD is a free, open-source Unix-like operating system emphasizing proactive security, code correctness, a unified base system, and portability across many hardware platforms.

OpenDocument (ODF): an open file format for office documents OpenDocument OpenDocument Format (ODF) is an open, XML-based container format for office documents (text, spreadsheets, presentations, drawings) intended for interoperability and long-term acce…

OpenGL — Open Graphics Library OpenGL OpenGL is a cross-platform application programming interface for rendering 2D and 3D graphics, providing a standardized way to use GPU acceleration across platforms and devices.

OpenOffice Draw — vector graphics and diagramming tool OpenOffice Draw OpenOffice Draw is the vector-graphics and diagram component of the Apache OpenOffice suite, offering connectors, page layout tools and common export/import options for diagrams, p…

OpenStep — NeXT's Portable Object-Oriented API and Operating Environment OpenStep OpenStep is NeXT's specification and implementation of an object-oriented application environment derived from NeXTSTEP, designed to run across multiple hardware and OS platforms a…

openSUSE — Community Linux distribution openSUSE openSUSE is a community-driven Linux distribution that provides stable and rolling-release editions, powerful system tools and an open build infrastructure for developers, sysadmin…

OpenVMS: a resilient enterprise operating system OpenVMS OpenVMS is a multiuser, multitasking OS originally by Digital Equipment Corporation for VAX hardware, later ported to Alpha and Itanium. It is known for clustering, availability an…

OpenVPN: protocol, features, security, history and common uses OpenVPN OpenVPN is an open-source VPN protocol and software suite widely used for secure remote access, site-to-site tunnels, and flexible deployment across platforms and networks.

OpenWrt: a customizable Linux-based firmware for network devices OpenWrt OpenWrt is a community-driven, Linux-based operating system for routers, switches and other network hardware that provides a package system, advanced features and a configurable we…

OpenZaurus — Debian-based Linux for Sharp Zaurus PDAs OpenZaurus OpenZaurus was a community Debian-derived embedded Linux distribution for Sharp Zaurus PDAs, providing lightweight ARM images, package management, alternative GUIs, and a platform…

Opera (web browser) Opera is a cross-platform web browser known for integrated features, data-compression mobile editions, and an early role introducing tabbed browsing and Speed Dial.

Operating system (OS): overview, components, history and uses Operating system An operating system manages hardware and software resources, provides common services to programs, and offers user interfaces. This article explains components, functions, types, h…

Opportunity (MER-B) — NASA's Mars Exploration Rover 'Oppy' Opportunity (rover) Opportunity (MER-B or 'Oppy') was a solar-powered Mars rover that operated from 2004 to 2018, surpassing its planned 90-sol mission to deliver major evidence that liquid water once…

Optical character recognition (OCR): technology, methods and applications Optical character recognition Optical character recognition (OCR) transforms printed or handwritten text into editable digital data. This article covers how OCR works, its history, common uses, limitations, and…

Optical disc drive A device that reads and writes data on optical discs (CD, DVD, Blu-ray) using a focused laser. Covers operation, components, common formats, uses and differences from other storage…

Optical fiber A slender strand of glass or plastic that guides light for communication, sensing, medical imaging and illumination using total internal reflection and specialized designs.

Optimization (computer science) Process of improving software, algorithms, or systems to use fewer resources, run faster, or meet other constraints; covers levels from hardware to networks and trade-offs involved…

OR gate (inclusive disjunction) in boolean logic and digital circuits OR gate An OR gate is a fundamental logic gate that outputs true when one or more inputs are true. This article explains its behavior, truth table, implementations, uses, and relations to…

Oracle Database Oracle Database is a widely used enterprise relational database management system with features for high availability, scalability, multi-model data support, and procedural extensi…

ORCID (Open Researcher and Contributor ID) ORCID ORCID iD is a persistent, unique 16-digit identifier for researchers and contributors that helps disambiguate names, link publications and activities, and integrate with publishers…

Organic light-emitting diode (OLED): principles, history, and applications Organic light-emitting diode OLEDs are thin, self-emissive displays and lighting devices made from organic films. This article explains how they work, their history, types, advantages, drawbacks, and common us…

OS X El Capitan (10.11) — Apple's performance‑focused macOS release OS X El Capitan OS X El Capitan (10.11) is Apple’s twelfth major desktop OS release, emphasizing performance, stability and security. Introduced in 2015, it refined Yosemite and laid groundwork fo…

OS X Mavericks (10.9) — Apple desktop operating system OS X Mavericks OS X Mavericks (10.9) is Apple's 2013 desktop operating system release introducing Finder tabs, Tags, Maps and iBooks on Mac, power-saving technologies and a shift to free distribu…

OS X Mountain Lion (10.8) — Apple’s 2012 Macintosh operating system OS X Mountain Lion OS X 10.8 Mountain Lion is Apple's 2012 release for Mac computers, emphasizing iCloud, Notification Center, Messages, Gatekeeper and closer integration with iOS features and servic…

OS X Yosemite (version 10.10) OS X Yosemite OS X Yosemite (10.10) is a major macOS release from Apple that introduced a flatter, translucent design and Continuity features integrating Mac and iOS devices, released after its…

Oscilloscope — Instrument for Displaying Electrical Signals Oscilloscope A technical overview of oscilloscopes: what they are, main parts and controls, types and history, common applications, and distinctions from related test instruments.

Output device (computer peripheral) Output device Hardware that presents processed information from a computer to the user or environment, including displays, printers, speakers, and actuators; types, functions, history and uses.

Oven: Types, Function, History and Uses Oven An oven is an insulated chamber that supplies controlled heat for cooking, drying or industrial processes. This article explains types, parts, history, typical uses and safety cons…

Overclocking: Increasing the speed of CPUs, GPUs and other components Overclocking Overclocking is the practice of running electronic components faster than their factory rates to gain performance. This article explains methods, risks, cooling, uses, and safer al…

Overhead projector: design, history, and educational uses Overhead projector Overview of the overhead projector (OHP): how it works, key parts, historical development, classroom and meeting uses, and reasons it was largely superseded by digital devices.

Pac-Man: the iconic 1980 arcade maze game Pac-Man Pac-Man is a landmark 1980 arcade maze game by Namco; a simple but deep design with ghosts, power pellets, cutscenes and a lasting cultural legacy.