H.264 is the block-based video codec standard, also called AVC, that compresses video for streaming, broadcast, cameras and conferencing on almost any…
H.265, also called HEVC, is a video compression standard that delivers similar quality to H.264 at a substantially lower bitrate, notably for…
Hallucination in language models is fluent, confident output that is false, unsupported or inconsistent with the given source, such as invented facts.
Hand tracking lets an XR headset follow the position and finger joints of bare hands with cameras, so users can point, pinch…
Hard light is light from a source that is small relative to the subject, producing sharp-edged shadows, bright specular highlights and strong…
A hard link in a Linux filesystem is an additional directory entry that points to the same inode as an existing file,…
Hardware acceleration moves demanding tasks such as rendering, video decoding and AI inference from the CPU to specialized units like the GPU.
A hardware wallet is a dedicated physical device that stores crypto private keys offline and signs transactions internally, so the keys never…
A hash function in cryptography maps data of any size to a fixed-length digest that is one-way and collision-resistant, used for integrity…
A hash index is a database index that maps each key through a hash function to a bucket, giving fast equality lookups…
A hash table is a data structure that maps keys to values through a hash function, giving average constant-time lookup, insertion and…
HAVING is the SQL clause that filters groups produced by GROUP BY using conditions on aggregate values such as COUNT, SUM or…
An HD map is a centimeter-accurate, machine-readable road map giving autonomous vehicles lane geometry, traffic rules and landmarks for localization.
An HDD is a storage device that records data magnetically on spinning platters read by moving heads, offering cheap capacity at mechanical…
HDMI, the High-Definition Multimedia Interface, is a digital connection that carries uncompressed video, audio and control data between devices and displays.
HDR (high dynamic range) in displays is the ability to show brighter highlights, deeper shadows and wider color than standard dynamic range…
HDR photography captures and renders scenes whose brightness range exceeds a single exposure, usually by merging bracketed frames and tone mapping them.
HDR10 is the open high dynamic range video format that combines PQ encoding, Rec. 2020 color, 10-bit depth and static metadata for…
HDR10+ is an HDR video format that adds dynamic, scene-by-scene metadata to HDR10 so displays can tone map each shot to their…
Heading structure is the logical hierarchy of H1 to H6 headings on a page, which helps readers and search engines understand its…
Headless architecture separates a backend that manages content and data from the frontends that present it, connecting them through APIs.
Headless commerce is an e-commerce architecture that separates the customer-facing storefront from the backend commerce engine, linked through APIs.
Headroom in audio recording is the margin in decibels between the normal operating level of a signal and the maximum level before…
A health check is an automated probe that tests whether a server or service is working correctly, feeding monitoring, alerts and load…
A heat sink is a passive metal component that draws heat away from a processor or other chip and releases it into…
A heatmap in data visualization encodes values in a grid of cells as color, revealing patterns, clusters and outliers across two dimensions.
Helm is the package manager for Kubernetes, bundling manifests into versioned charts that are installed, upgraded and rolled back as releases.
High availability is a server design goal that keeps a service running through component failures by removing single points of failure and…
A high-risk AI system is an AI system that the EU AI Act subjects to strict duties because it affects safety or…
High-speed sync is a flash mode that pulses the flash rapidly so it can light the whole frame at shutter speeds faster…
A higher-order function is a function that takes other functions as arguments or returns a function, a core building block of functional…
Highlight recovery in image processing restores detail in very bright areas of a photo by using unclipped raw data, channel reconstruction and…
HLG, or Hybrid Log-Gamma, is a backward-compatible HDR video transfer function built for live broadcast that needs no dynamic metadata.
HLS (HTTP Live Streaming) is an adaptive streaming protocol that delivers video as short HTTP segments listed in playlists, at several bitrates.
Hreflang is an annotation that tells search engines which language and regional versions of a page exist, so each user sees the…
A hreflang cluster in international SEO is the complete set of language or regional page versions that reference each other through reciprocal…
An HRTF, or head-related transfer function, describes how the head, torso and outer ears filter sound from each direction before it reaches…
An HS code is the standardized six-digit product classification used worldwide to determine customs duties, taxes and rules for traded goods.
HSL is a color model that describes colors by hue, saturation and lightness, making screen colors easier to adjust, compare and organize…
HSTS (HTTP Strict Transport Security) tells browsers to reach a site only over HTTPS, blocking protocol downgrades and certificate click-through.
An HTML attribute is a name-value pair in an element's start tag that configures the element's behavior, identity, presentation or accessibility.
An HTML element is a single unit of a web document, made of tags, attributes and content, that the browser turns into…
HTML5 is the modern generation of HTML, now the WHATWG Living Standard, adding semantic elements, native media, rich forms and APIs for…
htop is an interactive, color terminal process viewer for Linux that shows per-core CPU, memory, load and every process in a scrollable,…
HTTP, the Hypertext Transfer Protocol, is the stateless request-response application protocol that clients and servers use to exchange web resources.
HTTP/2 is the second major version of the HTTP protocol, carrying requests as binary frames over multiplexed streams on one TCP connection.
HTTP/3 is the third major version of HTTP, carrying web requests over QUIC and UDP to avoid head-of-line blocking and speed up…
HTTPS is HTTP carried over an encrypted TLS connection, protecting web traffic against eavesdropping and tampering and authenticating the server.
Hue is the attribute of color that names its position on the color wheel, such as red, green or blue, independent of…
A human approval gate pauses an AI automation workflow until an authorized person reviews and approves, edits or rejects the proposed action.