- October 9, 2026Zstandard, or zstd as short version, is a fast lossless compression algorithm, targeting real-time compression scenarios at zlib-level and better…
- October 9, 2026eXtensible Stylesheet Language Transformations (XSLT) is a declarative language used to convert XML documents into other XML documents, HTML, PDF,…
- October 9, 2026XHTML is a term that was historically used to describe HTML documents written to conform with XML syntax rules.
- October 9, 2026XLink is a W3C standard which is used to describe links between XML and XML or other documents.
- October 9, 2026In programming languages such as JavaScript, a wrapper is a function that is intended to call one or more other…
- October 9, 2026The World Wide Web—commonly referred to as WWW, W3, or the Web—is a system of interconnected public webpages accessible through…
- October 9, 2026A WindowProxy object is a wrapper for a Window object.
- October 9, 2026Whitespace refers to characters which are used to provide horizontal or vertical space between other characters.
- October 9, 2026WebVTT (Web Video Text Tracks) is a W3C specification for a file format marking up text track resources in combination…
- October 9, 2026WebRTC (Web Real-Time Communication) is an API that can be used by video-chat, voice-calling, and P2P-file-sharing Web apps.
- October 9, 2026WebSocket is a protocol that allows for a persistent TCP connection between server and client so they can exchange data…
- October 9, 2026WebKit is a framework that displays properly-formatted webpages based on their markup.
- October 9, 2026WebIDL is the interface description language used to describe the data types, interfaces, methods, properties, and other components which make…
- October 9, 2026WebDAV (Web Distributed Authoring and Versioning) is an HTTP Extension that lets web developers update their content remotely from a…
- October 9, 2026WebGL (Web Graphics Library) is a JavaScript API that draws interactive 2D and 3D graphics.
- October 9, 2026A web server is a piece of software that often runs on a hardware server offering service to a user,…
- October 9, 2026Web standards are rules established by international standards bodies that define how the Web works (and which sometimes control the…
- October 9, 2026Web performance is the objective time from when a request for content is made until the requested content is displayed…
- October 9, 2026The Web Accessibility Initiative (WAI) is an effort by the W3C to develop standards and guidelines to help everyone building…
- October 9, 2026Web Content Accessibility Guidelines (WCAG) is a recommendation published by the Web Accessibility Initiative (WAI) group at the W3C, outlining…
- October 9, 2026The World Wide Web Consortium (W3C) is an international body that maintains Web-related rules and frameworks.
- October 9, 2026VoIP (Voice over Internet Protocol) is a technology used to transmit voice messages over IP (Internet Protocol) networks.
- October 9, 2026A void element is an element in HTML that cannot have any child nodes (i.e., nested elements or text nodes).
- October 9, 2026The portion of the viewport that is currently visible is called the visual viewport.
- October 9, 2026In computer graphics, a viewport represents a polygonal (normally rectangular) area that is currently being viewed.
- October 9, 2026Browser vendors used to add prefixes to experimental or nonstandard CSS properties and JavaScript APIs, so developers could experiment with…
- October 9, 2026In the context of data or an object wrapper around that data, the value is the primitive value that the…
- October 9, 2026A Universally Unique Identifier (UUID) is a label used to uniquely identify a resource among all other resources of that…
- October 9, 2026UX is an acronym that stands for User eXperience.
- October 9, 2026UTF-16 is a character encoding standard for Unicode.
- October 9, 2026UTF-8 (UCS Transformation Format 8) is the World Wide Web's most common character encoding.
- October 9, 2026A Uniform Resource Locator (URL) is a text string that specifies where a resource (such as a web page, image,…
- October 9, 2026A user agent is a computer program representing a person, for example, a browser in a Web context.
- October 9, 2026A URI (Uniform Resource Identifier) is a string that refers to a resource.
- October 9, 2026Unix time is a method to represent a timestamp, and is usually defined as the number of seconds since the…
- October 9, 2026User Interface (UI) is anything that facilitates the interaction between a user and a machine.
- October 9, 2026UDP (User Datagram Protocol) is a long standing protocol used together with IP for sending data when transmission speed and…
- October 9, 2026User Agent Accessibility Guidelines (UAAG) is a recommendation published by the Web Accessibility Initiative group at the W3C, explaining how…
- October 9, 2026In JavaScript, a truthy value is a value that is considered true when encountered in a Boolean context.
- October 9, 2026Trident (or MSHTML) was the proprietary rendering engine that powered Internet Explorer.
- October 9, 2026Tree shaking is a term commonly used within a JavaScript context to describe the removal of dead code.
- October 9, 2026Transport Layer Security (TLS), formerly known as Secure Sockets Layer (SSL), is a protocol used by applications to communicate securely…
- October 9, 2026Transient activation (or "transient user activation") is a window state that indicates a user has recently directly and meaningfully interacted…
- October 9, 2026The top layer is a specific layer that spans the entire width and height of the viewport and sits on…
- October 9, 2026Time to Interactive (TTI) is a non-standardized web performance 'progress' metric defined as the point in time when the last…
- October 9, 2026A TLD (top-level domain) is the most generic domain in the Internet's hierarchical DNS (domain name system).
- October 9, 2026Trust On First Use (TOFU) is a security model in which a client needs to create a trust relationship with…
- October 9, 2026Time to First Byte (TTFB) refers to the time between the browser requesting a page and when it receives the…
- October 9, 2026Thread in computer science is the execution of running multiple tasks or programs at the same time.
- October 9, 2026Throttling originally meant slowing down the rate of fluid flow using an obstruction.
- October 9, 2026The Khronos Group is an open, non-profit, member-driven consortium of over 150 industry-leading companies.
- October 9, 2026TCP slow start is an algorithm that helps discover the available network bandwidth for packet transfer, and balance transmission speed…
- October 9, 2026In 3D graphics, a texel (short for "texture pixel") is an individual element of a texture.
- October 9, 2026TCP (Transmission Control Protocol) is an important network protocol that lets two hosts connect and exchange data streams.
- October 9, 2026TCP (Transmission Control Protocol) uses a three-way handshake (aka TCP-handshake, three message handshake, and/or SYN-SYN-ACK) to set up a TCP/IP…
- October 9, 2026In HTML, a tag is used for creating an element.
- October 9, 2026Serializable objects are objects that can be serialized and later deserialized in any JavaScript environment ("realm").
- October 9, 2026SEO (Search Engine Optimization) is the process of making a website more visible in search results, also termed improving search…
- October 9, 2026In programming, Semantics refers to the meaning of a piece of code — for example "what effect does running that…
- October 9, 2026A CSS selector is the part of a CSS rule that describes what elements in a document the rule will…
- October 9, 2026A search engine is a software system that collects information from the World Wide Web and presents it to users…
- October 9, 2026A secure context is a Window or Worker in which certain minimum standards of authentication and confidentiality are met.
- October 9, 2026An SDK (Software Development Kit) is an integrated collection of tools that a developer can use to create software for…
- October 9, 2026SCTP (Stream Control Transmission Protocol) is an IETF standard for a transport protocol which enables the reliable, in-order transmission of…
- October 9, 2026A scroll container is an element box whose content can be scrolled, whether or not scroll bars are present.
- October 9, 2026Scroll snapping is a feature where content "snaps" to a specific position when a scroll operation finishes, such as a…
- October 9, 2026Scroll chaining refers to the behavior observed when a user scrolls past the Scroll boundary of a scrollable element, causing…
- October 9, 2026A scroll boundary is the point at which a scrollable element cannot be scrolled any further in a particular direction,…
- October 9, 2026In an HTML document, script-supporting elements are those elements that don't directly contribute to the appearance or layout of the…
- October 9, 2026The scope is the current context of execution in which values and expressions are "visible" or can be referenced.
- October 9, 2026Screen readers are software applications that attempt to convey what is seen on a screen display in a non-visual way,…
- October 9, 2026SCM (Source Control Management) is a system for managing source code.
- October 9, 2026An HTTP method is safe if it doesn't alter the state of the server.
- October 9, 2026In cryptography, salt is random data added to a password before it is hashed.
- October 9, 2026REST (Representational State Transfer) refers to a group of software architecture design constraints that bring about efficient, reliable and scalable…
- October 9, 2026A response header is an HTTP header that can be used in an HTTP response and that doesn't relate to…
- October 9, 2026A request header is an HTTP header that can be used in an HTTP request to provide information about the…
- October 9, 2026The following are treated as replaced elements only in specific cases:
- October 9, 2026In web security, a replay attack happens when an attacker intercepts a previously-sent message and resends it later to get…
- October 9, 2026A representation header (or 'representation metadata') is an HTTP header that describes how to interpret the data contained in the…
- October 9, 2026Repaint happens when a browser redraws a web page to show the visual updates resulting from a UI change, such…
- October 9, 2026Render-blocking refers to any part of the process of loading a website that blocks the rendering of the user interface.
- October 9, 2026A relying party (RP) is an entity that needs to control access to a resource and, to do so, needs…
- October 9, 2026Regular expressions (or regex) are rules that govern which sequences of characters come up in a search.
- October 9, 2026A registrable domain is a domain that can be (or has already been) registered by an individual or an organization…
- October 9, 2026Reflow happens when a browser recalculates the position and geometry of certain parts of a webpage, such as after an…
- October 9, 2026Real User Monitoring (RUM) measures the performance of a page from real users' machines.
- October 9, 2026The act of a function calling itself, recursion is used to solve problems that contain smaller sub-problems.
- October 9, 2026Reading order refers to the order in which content is accessed, for example when read out by a screen reader,…
- October 9, 2026A raster image is an image file defined as a grid of pixels.
- October 9, 2026In computing, especially in networking, rate limiting means controlling how many operations can be performed in a given amount of…
- October 9, 2026RAIL, an acronym for Response, Animation, Idle, and Load, is a performance model originated by the Google Chrome team in…
- October 9, 2026QUIC is a multiplexed transport protocol implemented on UDP.
- October 9, 2026Quality values, or q-values and q-factors, are used to describe the order of priority of values in a comma-separated list.
- October 9, 2026A quaternion is the quotient of two 3D vectors and is used in 3D graphics and in accelerometer-based sensors to…
- October 9, 2026Prefetching refers to the practice of speculatively fetching documents or subresources in the background for pages that the user is…
- October 9, 2026For a computer connected to a network with an IP address, a port is a communication endpoint.
- October 9, 2026Polymorphism is the presentation of one interface for multiple data types.
- October 9, 2026POP3 (Post Office Protocol) is a very common protocol for getting emails from a mail server over a TCP connection.
- October 9, 2026A polyfill is a piece of code (usually JavaScript on the Web) used to provide modern functionality on older browsers…
