Technology

PostScript: the page description language for printing and graphics Postscript PostScript is a stack-based page description language developed by Adobe for controlling printers and imaging systems. It describes pages as vector graphics, text and images and in…

Potentiometer — adjustable resistor and voltage divider Potentiometer A potentiometer is an adjustable resistor used to vary voltage or current, commonly in controls and sensors. Types include rotary, linear and trimmer; modern alternatives include d…

Power Glove: Mattel's early motion controller for the Nintendo Entertainment System Power Glove The Power Glove is a 1989 third‑party controller by Mattel for the NES that attempted hand‑motion input. It underperformed commercially but became a notable early experiment in gam…

Power loom A power loom is a mechanically driven loom that automates weaving. This article covers its operation, main parts, historical development from Cartwright to automated and shuttleles…

Power Pad: the floor controller for the NES Power Pad A floor-based input mat for the Nintendo Entertainment System (NES), the Power Pad let players use hands and feet to control games, notable for games like World Class Track Meet an…

Power station (electricity generation facility) Power station An overview of power stations: how they generate electricity, main types and components, operational roles, historical development, uses, and environmental and technical distinctio…

Power supply unit (PSU) Power supply unit A power supply unit converts mains alternating current to the direct currents used by electronic components. PSUs define form factor, connectors, efficiency ratings, protections an…

PowerBook: Apple's Professional Laptop Line (1991–2006) PowerBook Overview of the PowerBook family of laptop computers by Apple (1991–2006): design innovations, development, notable models, uses, awards, and its legacy leading to the MacBook.

Pre-shared key (PSK): shared secrets for symmetric cryptography Pre-shared key A pre-shared key (PSK) is a secret shared in advance between parties for symmetric cryptographic systems. Covers formats, distribution, common uses (Wi‑Fi, VPN, IoT), security risk…

Preamplifier: function, types, history, and role in audio systems Preamplifier A preamplifier boosts weak audio signals to line level for processing or distribution. Covers functions, common types (mic, phono, instrument), history (tubes to transistors), and…

Predictive Failure Analysis (PFA) — disk failure monitoring technology Predictive Failure Analysis Predictive Failure Analysis (PFA) flags likely storage device failures by monitoring drive parameters. Originating at IBM, it feeds into S.M.A.R.T. and helps plan replacements and…

Presentation software Computer applications designed to create and display slide-based content for talks, lessons, reports and multimedia displays, with tools for editing, graphics and live presentation…

Prestel — the UK’s pioneering Viewdata videotex service Prestel Prestel was the British Post Office’s Viewdata videotex system, launched in 1979. It delivered pages of information to TV terminals over telephone lines and influenced later online…

Primary cell (disposable battery) Primary cell A primary cell is a single-use electrochemical cell (disposable battery) that delivers electrical energy until exhausted; commonly used in low-drain devices and available in severa…

Print server (printer server) Print server A print server connects printers to a network, accepting jobs from clients and managing queues, access, protocols and spooling for centralized printing in homes, offices and data c…

Printed circuit board (PCB): design, construction, types and applications Printed circuit board A printed circuit board (PCB) mechanically supports and electrically interconnects electronic components via conductive patterns on a non-conductive substrate. This article explain…

Printer (electronic output device) Printer A printer is a device that produces text and images on physical media. Modern printers include inkjet, laser, thermal, impact and 3D types and serve home, office and industrial use…

Printer (publishing): industry roles, processes, and types Printer (publishing) An overview of printers in publishing: who they are, how printing is organized, common technologies and product types, historical context, and distinctions among newspaper, book an…

Printer Command Language (PCL): overview, versions, and uses Printer Command Language Printer Command Language (PCL) is Hewlett‑Packard's widely used family of page description protocols. This article summarizes PCL's purpose, major versions, compatibility and commo…

Printing: methods, history, and social impact Printing Overview of printing: how it transfers ink to paper, major techniques, historical development from woodblock and movable type to digital, and its cultural and economic effects.

Printing press: history, technology, and cultural impact Printing press Comprehensive overview of the printing press: mechanisms, historical development from woodcut and movable type to steam and digital presses, and the social, cultural, and economic…

Pro Tools: Professional Digital Audio Workstation — Features and Uses Pro Tools Pro Tools is a professional DAW for macOS and Windows used widely in music, post‑production and broadcast. This article explains its features, history, file support, workflows and…

Probe droid (Star Wars reconnaissance droid) Probe droid Fictional autonomous reconnaissance droids in the Star Wars franchise used for scouting, surveillance and target acquisition; notable appearances include The Empire Strikes Back an…

Process (computing): execution instance, lifecycle, and characteristics Process (computing) A computing process is a running instance of a program. This article explains what a process is, its parts and states, how operating systems manage processes, and how processes dif…

Process switching latency in operating systems Process switching latency Process switching latency is the delay an operating system incurs when changing execution from one process to another; it includes saving/restoring state, memory and cache effects,…

Programmable Logic Controller (PLC): Overview, Components, Uses and History Programmable logic controller A programmable logic controller (PLC) is a rugged digital computer used for industrial automation. This article explains how PLCs work, their parts, history, common uses, programmi…

Programmable Read-Only Memory (PROM) Programmable read-only memory Overview of PROM: what it is, how it differs from other ROM types, main variants (PROM, EPROM, EEPROM), programming methods, typical uses, and notable distinctions.

Computer programmer Programmer A computer programmer writes, tests and maintains software using programming languages and tools. Covers tasks, tools, languages, work contexts, education, practices, history and r…

Progressive scan (video display method) Progressive scan Progressive scan is a method of producing images by drawing every line of a frame in sequence. Widely used in digital displays, it reduces interlacing artifacts and is standard for…

Project Athena: MIT’s campus computing initiative (1983–1991) Project Athena Project Athena was an MIT-led collaboration (with DEC and IBM) to create a shared, networked computing environment for teaching, producing technologies like the X Window System and…

Proprietary software Software distributed under licenses that restrict access to and modification of source code; contrasts with free/open-source models and raises issues of control, security, and busi…

Prosthesis An overview of prostheses: devices that replace missing body parts, their components, types, history, uses, rehabilitation, and current research toward improved function and sensat…

Prototype Comprehensive overview of prototypes: definitions, common types, development process, fidelity levels, purposes, methods, and distinctions from proofs of concept, mockups, pilots,…

Proximity fuze (VT fuze): sensor-triggered detonation device Proximity fuze A proximity fuze detonates a projectile when it nears a target, using radio, optical or other sensors. It improved anti-aircraft and artillery effectiveness and is used in many mod…

Pseudocode: informal notation for algorithms and program design Pseudocode Pseudocode is a human-readable, language-agnostic way to describe algorithms and program logic, used for planning, teaching, documentation, and communicating ideas without strict s…

Public-key cryptography: principles, history, and applications Public-key cryptography Overview of public-key (asymmetric) cryptography: how key pairs work, main functions (encryption and signatures), history, practical uses, trust models, and modern challenges.

Pump — device for moving liquids and other fluids Pump A pump is a mechanical device that moves fluids by converting energy into flow and pressure. This article explains how pumps work, major types, history, common uses, and practical…

Punched card: physical data storage and control medium Punched card A punched card is a stiff paper card in which patterns of holes encode data or control instructions. Widely used from the 19th century through mid-20th, it powered looms, census ta…

Punched tape: a historic data-storage medium Punched tape Punched tape is a long strip of material with holes that encode data. Used from early mechanical looms to mid-20th-century teleprinters and early computers, it shaped automation an…

Puppet (software) Open-source configuration management and deployment tool that automates system configuration using a declarative language, modules and a client–server model; also available as an e…

Puppy Linux — a lightweight, portable GNU/Linux distribution Puppy Linux Puppy Linux is a compact, user-oriented GNU/Linux distribution designed to run from removable media or old hardware, known for small size, speed, and tools for frugal installation…

Push-button Switches: Types, Operation, Design, and Applications Push-button Overview of push-button switches: types (momentary vs latching), internal mechanisms, design factors, electrical ratings, ergonomics and common applications from consumer electroni…

PuTTY — a versatile SSH and terminal emulator PuTTY PuTTY is a free, open-source terminal emulator and network client for SSH, Telnet, rlogin, and raw TCP, originally for Windows and since ported to other platforms; includes utiliti…

Puzzle video game A genre of video games centered on solving puzzles using logic, pattern recognition, spatial reasoning, or strategy; includes many subgenres and has broad casual and educational ap…

Q*bert Q*bert is a 1982 isometric arcade puzzle game by Gottlieb in which a hopping protagonist changes cube colors on a pyramid while avoiding enemies. It spawned many ports, sequels and…

Qanat — traditional underground water channels Qanat A qanat is a gently sloping underground channel with vertical access shafts that conveys groundwater by gravity to arid settlements for irrigation and drinking water.

QBasic: Microsoft’s beginner-oriented BASIC interpreter and IDE QBasic QBasic is a simplified Microsoft BASIC interpreter and integrated editor once bundled with MS‑DOS and early Windows. Designed for learning and small utilities, it remains popular f…

QNX: a microkernel real-time operating system for embedded devices QNX QNX is a Unix-like real-time operating system built on a microkernel. It is widely used in automotive, medical, industrial and consumer embedded systems for its determinism, modula…