A p-value is the probability of seeing results at least as extreme as those observed if the null hypothesis were true, used…
PaaS, or Platform as a Service, is a cloud model in which the provider runs the servers and runtime so developers deploy…
A package manager is a tool that installs, updates and removes software packages automatically, resolving dependencies from trusted repositories.
Packet capture is the recording of network packets as they cross an interface, saved to a file for detailed protocol analysis and…
Packet loss is the share of network packets that never reach their destination, a key network monitoring metric for congestion, faults and…
Pacman is the package manager of Arch Linux that installs, upgrades and removes packages and synchronizes the system with its repositories.
PageSpeed Insights is a Google web testing tool that reports real-user Core Web Vitals and a Lighthouse lab audit for any public…
PAM, the Pluggable Authentication Modules framework, lets Linux services delegate login, password and session checks to configurable module stacks.
A pancake lens is a folded optical design in XR headsets that bounces light between polarizing layers to shorten the distance from…
Panorama stitching in photography merges overlapping frames into one wide or high-resolution image by aligning, projecting and blending them.
Parallelism in programming means executing several computations at the same instant on multiple cores or processors to finish a workload faster.
A parameter in programming is a named variable in a function definition that receives a value, called an argument, each time the…
Parquet is an open columnar file format for analytical data that stores values by column with compression, encoding and statistics for fast…
Partitioning splits a large database table into smaller physical pieces by a key, so queries and maintenance touch only the relevant part.
A passkey is a FIDO2 credential based on a public and private key pair that replaces passwords with phishing-resistant sign-in bound to…
Patch Tuesday is the monthly day, the second Tuesday, on which Microsoft releases security and quality updates for Windows and its other…
PATH is the environment variable listing the directories a Linux shell searches, in order, to find the executable behind a typed command…
Path planning computes a collision-free route for a robot from its start to a goal, optimizing criteria such as length, travel time,…
Path tracing is a rendering method that simulates light bouncing through a scene to produce all lighting, shadows and reflections in a…
Pay-as-you-go is the cloud pricing model in which customers pay only for resources actually consumed, metered per second, hour, request or gigabyte.
Payment fraud is the unauthorized or deceptive use of payment methods in online stores, from stolen card data to false chargeback claims…
A payment gateway is the service that securely captures payment details at checkout and routes authorization requests from a store to the…
A payment processor is the company or system that routes card transactions between a merchant, the card networks and the banks, then…
PCI DSS is the card industry security standard that every e-commerce merchant accepting card payments must meet to protect cardholder data.
PCIe is the serial point-to-point interface that connects graphics cards, NVMe drives and other devices to the CPU and chipset on a…
PCM, or pulse-code modulation, is the standard method of digital audio that samples a waveform at regular intervals and stores each sample…
Peak luminance in HDR video is the highest brightness, in nits, that a display can produce or that content is mastered to…
Penetration testing is an authorized simulated attack in which security testers exploit vulnerabilities to show their real business impact before attackers do.
Per-seat pricing is a SaaS pricing model that charges a fixed recurring fee for each named user who has access to the…
A percentile is the value below which a given percentage of observations in a dataset falls, used in statistics to describe position…
Perplexity is a model evaluation metric for language models that measures how well a model predicts text; lower perplexity means less surprise…
A persona in UX design is a research-based archetype of a user group that captures goals, behaviors and context to guide product…
Personal data is any information relating to an identified or identifiable natural person, the central concept that triggers data protection obligations.
Perspective in photography composition is how camera position shapes the apparent size, distance and spatial relationships of objects within the frame.
pg_dump is the PostgreSQL utility that creates a consistent logical backup of one database as an SQL script or an archive restorable…
Phantom power in audio recording is DC voltage, usually 48 V, sent through balanced microphone cables to power condenser microphones and active…
Phase detection AF focuses a camera by comparing two images from opposite sides of the lens, which reveals both the direction and…
A phaser is an audio effect that sweeps notches through the spectrum by mixing a signal with an all-pass filtered copy, creating…
A PHEV, or plug-in hybrid electric vehicle, combines a combustion engine with a rechargeable battery that can be charged from the grid…
Phishing is a social engineering attack in which fraudulent messages impersonate trusted parties to steal credentials, money or install malware.
A photographic negative is a developed film or plate image with reversed tones, used as the master from which any number of…
Photolithography is the semiconductor manufacturing process that uses light and a photomask to print circuit patterns onto silicon wafers, layer by layer.
PHP is a general-purpose scripting language built for server-side web development, running behind content systems, online shops and web APIs.
PHP-FPM is the FastCGI process manager that runs pools of PHP worker processes behind a web server such as Nginx, Apache or…
A PHP worker pool is a managed set of PHP-FPM processes that execute requests in parallel, and its size largely decides server…
Physical AI is artificial intelligence that perceives, reasons about and acts in the physical world through robots, vehicles and other machines.
Pick and pack is the e-commerce fulfillment process of collecting ordered items from warehouse storage and packing them into shipment-ready parcels.
Pick and place is the robot manipulation task of grasping an object at one location and releasing it at another, combining perception,…
PID is a feedback control law that adds proportional, integral and derivative actions on the error to drive a robot joint, wheel…
A pie chart is a circular data visualization that divides a whole into slices whose angles are proportional to each category's share…