H

H for http

abbreviation / acronyms	Term	Definition
h-menu	Hierarchical menu	A pull-down menu that has sub-menus. The sub-menus are indicated by arrows. Putting the pointer on the item that has an arrow opens up the sub-menu.
H/S LAN	High-Speed Local-Area Network	A LAN operating at 4 Mbits per second or more to facilitate rapid exchange of files, mail, etc., within a broader departmental or divisional environment.
H&H	Hoot & Holler	A dedicated point-to-point voice facility between international offices of a trading facility.
H3C	(previous) Huawei Technologies—3Com	HP company, supplier of routers, Ethernet switches, wireless LAN, security and Voice/Video over IP and network management systems www.h3c.com
HA	high availability	Pertaining to a clustered system that is reconfigured when node or daemon failures occur, so that workloads can be redistributed to the remaining nodes in the cluster. The ability of IT services to withstand all outages and continue providing processing capability according to some predefined service level.
HAAT	Height Above Average Terrain	a measure of an antenna's height above average terrain. This value is used by the FCC in determining compliance with height limitations and transmitting powers for high sites.
HACMP	High-Availability Cluster Multi-Processing	Software that provides host clustering, so that jobs are moved to other hosts within the cluster if one host fails.
Hactivism	from "hack" and "activism"	the concept of hacking into a Web site or computer system in order to communicate a politically or socially motivated message.
HAD	Holographic Autostereoscopic Display	Simple conversion of LCD technology, replacing the LCD's backlight with an HOE (holographic optical element)
HADR	high availability disaster recovery	A disaster recovery solution that uses log shipping and provides data to a standby system if a partial or complete site failure occurs on a primary system.
HAE	Height Above Ellipsoid	Vertical difference between a reference ellipsoid model and the known, or derived, elevation at a given spatial location (typically in meters).
HAL	Hardware Abstraction Layer	A translation protocol in Windows NT for porting NT to another platform.
HAN	home area network	a network contained within a user's home that connects a person's digital devices, from multiple computers and their peripheral devices to telephones, VCRs, televisions, video games, home security systems, "smart" appliances, fax machines
HARC	Hitachi Asynchronous Remote Copy	A remote copy function for HDS storage products. HARC allows movement of large amounts of data over any distance with full data integrity and minimal impact on performance.
HARQ	Hybrid Automatic Repeat reQuest	a sheme wherein information blocks are encoded for partial error correction at receiver and additional, uncorrected errors are retransmitted.
HASP	Houston Automatic Spooling Program	A mainframe spooling program that provides task management, job management, and data management functions.
HAT	Heap Analysis Tool	Tool for tracking down heap problems in Java programs
HAVi	Home Audio Video interoperability	a vendor-neutral audio-video standard aimed specifically at the home entertainment environment.
HBA	host bus adapter	An adapter used to connects a host computer to a storage network.
HCI	Host Controller Interface Human-Computer Interaction	BlueTooth technology The study of how humans interact with computers, used to design computers which are easy for humans to use.
HCL	Hardware Compatibility List	A list of computers and peripherals that have been tested by Microsoft to work with Windows NT or Windows 2000.
HCM	human capital management	Social software covers a range of functionality, from wikis and blogs to social networks and social bookmarking.
HCO	High-Capacity Optical	HCO drives use blue-laser technology and standard 120-millimeter CD/DVD-size discs for as much as six times the capacity of traditional 5.25-inch magneto-optical (MO) technology.
HCR	Huffman Codeword Reordering	MPEG-4 Audio Error Resilience (ER) technique that avoids error propagation within spectral data
HCT	hardware compatibility tests	A suite of tests from WHQL to verify hardware and device driver operations under a specific operating environment. These tests exercise the combination of a device, a software driver, and an operating system under controlled conditions.
HD / HDD	Hard Disk Drive	permanent storage medium used on computers. A HDD consists of a number of rigid discs that store all of the computer programs and data on the computer, even when the power to the computer is switched off.
HD DVD	high-density DVD	a high-density optical disc similar to, but not compatible with, BLU-RAY DISC, formerly marketed by Toshiba but discontinued in 2008.
HDA	Head Disk Assembly	The mechanical parts of a disk drive, including the read/write heads, platters, and other non-electronic components.
HDCP	High-bandwidth Digital Content Protection	a specified method from Intel for protecting copyrighted digital entertainment content that uses the DVI by encrypting its transmission between the video source and the digital display (receiver).
HDLC	High Level Data Link Control	An ITU-TSS link layer protocol standard for point-to-point and multi-point communications.
HDMI	High-Definition Multimedia Interface	HDMI is a digital interface whose purpose is to permit the transmission of audio and video signals through a single cable, while supporting faster data rates than its normal counterparts. http://www.hdmi.org/
HDML	Handheld Device Markup Language	Specifications allow Internet access from wireless devices such as handheld personal computers and smart phones.
HDR	header label	A set of information on a diskette or tape that describes the contents of the diskette or tape. The label or data set label that precedes the data records on a unit of recording medium.
HDR	High-dynamic-range imaging or High-dynamic-range rendering host-discovered resource	digital imaging or an image rendering technique A set of storage hardware resources that are attached to a host system and are available on the operating system.
HDS	Hitachi Data Systems	A vendor of enterprise and modular storage systems and software. HDS is a wholly owned subsidiary of Tokyo-based electronics firm Hitachi, Ltd.
HDSL	High bit-rate Digital Subscriber Line	Provides repeaterless digital transmission at 2Mbit/s for about 12000 feet (4km) over twisted pair.
HDTP	Handheld Device Transport Protocol	It presents the HDML to the HDML interpreter in an appropriate format. Developed by HTTP://WWW.PHONE.COM for use in wireless applications.
HDTV	High Definition television	High Definition television means broadcast of television signals with a higher resolution than traditional formats allow. It's a step change in television technology which provides far clearer and more detailed pictures than normal "standard definition" TV.
HDx / HD	Half duplex	A device can either receive or send data at a given time.
HE-AAC	High Efficiency Advanced Audio Coding	Lossy data compression scheme for streaming audio. It combines three techniques: AAC, Spectral Band Replication (SBR), and Parametric Stereo (PS)
HEC	Header Error Control	Using fifth octet in ATM cell header, ATM equipment may check for error and correct contents of header. Check character is calculated using CRC algorithm allowing single bit error in header to be corrected or multiple errors to be detected.
HEL	Hardware Emulation Layer	This provides software-based emulation of features that are not directly available in hardware.
HEP	horizontal enterprise portal	A portal that serves a broad population of users across an enterprise — unlike a VEP, which serves only a specific segment of this population
HERF	high energy radio frequency	A HERF gun is used to disrupt digital equipment such as computers by blasting them with HERF emissions.
HFC	Hybrid Fiber Coax	second generation cable TV infrastructure. HFC networks combine both optical-fiber and coaxial cable lines. Optical fiber runs from the cable head end to neighborhoods of 500 to 2,000 subscribers.
HFS	Hierarchical File System	HFS is the file system used for organizing files on a Macintosh hard disk. When a hard disk is formatted for a Macintosh computer, the hierarchical file system is used to create a directory that can expand as new files and folders are added to the disk.
HFS+	Hierarchical File System Plus	The Mac OS Extended file-system format. This format was introduced as part of Mac OS 8.1, adding support for filenames longer than 31 characters, Unicode representation of file and directory names, and efficient operation on very large disks.
HGFS	Host-Guest File System	VMware's name for the guest-visible aspect of a Shared Folder.
HGML	Hypertext General Markup Language	A formatting code for marking up text files, which makes up part of SGML.
HHO	Hard Hand Off	used in CDMA systems, describes a hand-off involving a frequency change.
HHT	Hand-Held Terminal	Hand-held programming terminal to communicate with a programmable logic controller (PLC) on the fly
HID	High-Intensity Discharge Human Interface Device	Light bulb technology used mainly in projectors The HID profile defines the protocols, procedures and features to be used by Bluetooth HID such as keyboards, pointing devices, gaming devices and remote monitoring devices.
HIDAM	hierarchical indexed direct access method	A database access method used for indexed access to records in a hierarchic direct organization. It provides indexed access to the root segments and pointer access to subordinate segments.
HIDS	Host based Intrusion Detection System	A system for detecting unauthorised access to a single computer. A HIDS may monitor logs or activity on network ports, or use other techniques to detect possible intrusions
HiFD	HIgh-capacity Floppy Disk	Sony term.
HighMAT	High-performance Media Access Technology	a set of standards co-developed by Microsoft and Matsushita (Panasonic) for CDs and DVDs that are created on personal computers but played back on consumer electronic devices such as CD players and DVD-equipped television sets.
HIL	Hardware-in-the-Loop	applications used by design and test engineers to evaluate and validate vehicle components during development of new systems
HIMEM	HIgh MEMory	A DOS and Windows extended memory manager.
HIP	Host Identity Protocol	host identification technology for use on IP networks, such as the Internet.
HIPAA	Health Insurance Portability and Accountability Act	An act passed by the U.S. congress in August 1996. HIPAA's directives call for the use of EDI in healthcare transactions, and for protecting the privacy of patient healthcare information.
HiPerLinks	High-Performance Links	A high-speed coupling-link technology introduced by IBM in 1997 for its S/390 mainframes.
Hiperspace	High-Performance Space	Introduced with ESA/370, a hiperspace is, in essence, an address space occupied only by data and to which access is controlled by hardware via special instructions.
HIPPI	HIgh Performance Parallel Interface	A high-speed communications bus used with supercomputers or high-speed LANs.
HIS	healthcare information system	A system or application used to manage hospital or other healthcare-related operations (such as financial, registration, scheduling and back-office functions); also called a "hospital information system."
HISAM	hierarchical indexed sequential access method	A database access method used for indexed access to records in a hierarchic sequential organization.
HITECH	Health Information for Economic and Clinical Health	Act collectively refers to the health information technology provisions included at Title XIII of Division A and Title IV of Division B of the ARRA.
HIToolbox	Human Interface Toolbox	A collection of procedural APIs that apply an object-oriented model to windows, controls, and menus for Carbon applications.
HKCC	HKey_Current_Config	Windows NT Registry key
HKLM	HKey_Local_Machine	Windows NT Registry key
HL7	Health Level 7	HL7 is a standard interface for exchanging and translating data between computer systems. HL7 is also a not-for-profit organization accredited by the American National Standards Institutes (ANSI) that develops standards for data transfer. http://www.hl7.org/
HLA	High Level Architecture	a general purpose architecture for distributed computer simulation systems. Using HLA, computer simulations can communicate to other computer simulations regardless of the computing platforms.
HLLAPI	High Level Language Application Programming Interface	used with IBM mainframes to allow PC's to communicate with the mainframe using an emulator.
HLR	Home Location Register	a database residing in a local wireless network that checks the identity of a local subscriber. HLR contains information about subscribers to a mobile network and registers subscribers for a particular service provider.
HMA	High Memory Area	Method to access the first 64kB segment above the 1MB boundary in DOS/Windows 16-bits
HMD	Head Mounted Display	A helmet with stereoscopic goggles for the wearer's eyes, and stereo headphones over the ears; used as an interface through which the wearer can experience a virtual reality environment.
HMP	Hybrid Multiprocessing	refers to a kind of multitasking which provides some elements of symmetric multiprocessing, using add-on IBM software called MP/2. IBM OS/2 supports HMP.
Honeynet	A network of honeypots.	A network of honeypots.
HOSED	Hardware Or Software Error Detected	General error not yet diagnosed.
HP	Hewlett-Packard HoneyPot	A manufacturer of workstations, electronic instrumentation and test equipment etc. Founded in 1939 by Stanford University graduates, William R. Hewlett and David Packard, HP is the original garage start-up. www.hp.com An Internet-attached server that acts as a decoy, luring in potential hackers in order to study their activities and monitor how they are able to break into a system
HPA	High Performance Addressing	A kind of display used on some multimedia notebook computers, that delivers high-quality graphics comparable to Active Matrix (TFT) Displays.
HPB	High Ping Bastard	Network multiplayer games attribute
HPC	High Performance Computing	HPC is a generic and relative term since the desktop computers of today are capable of the same performance as supercomputers from a few years back.
HPF	High Pass Filter	a telephony term. A signal filter which would be installed in a customer premises ADSL modem (ATU-R), which only allow higher frequency data to be delivered to the modem.
HPFS	High Performance File System	The file system for IBM OS/2.
HPGL	Hewlett-Packard Graphics Language	HP Language to describe vector graphics (usually for plotters)
HPIB	Hewlett Packard Interface Bus	Is a version of GPIB (also known as IEEE.488) and was used on Hewlett Packard (Now Aligent Technologies) lab equipment. Early versions used a different connector
HPNA	Home Phoneline Networking Alliance	An alliance to advance technologies for high-speed local-area networking over conventional phone wires. It was founded in 1998 by 3Com, AMD, AT&T Wireless Services, Compaq, Conexant Systems, HP, IBM, Intel, Lucent and Tut Systems.
HR	horizontal rule	tag used in HTML to indicate a horizontal rule.
HR/DSSS	High Rate/Direct Sequence Spread Spectrum Physical Layer	the enhanced physical layer defined by IEEE 802.11b which supports data transfer at up to 11Mbps.
HRAA	High Resolution Anti Aliasing	Technology found in the nVidia GeForce3 Chip
HRC	Hitachi Remote Copy	A controller-based remote-copy capability used in Hitachi Data Systems storage products.
HRMS	human resource management system	Business applications for the management of human resource (HR) transactions, best practices and enterprise reporting. Functions typically include core HR tracking, payroll and benefits.
HRPD	High Rate Packet Data	also known as TIA/EIA IS-856 or 1xEV-DO, is a packet data protocol in the 3G mobile communicaitons network based on CDMA2000.
HPR	High-Performance Routing	IBM's technology to enable users to send SNA traffic over frame and cell-based networks, making for more efficient communications.
HSB / HSV	Hue, Saturation, Brightness (or Value)	HSV is a way of defining a colour based on a colour wheel. Hue measures the angle around the colour wheel. The saturation indicates the radius on the colour wheel so indicates the proportion between dark to pure colour to white. Value indicates the brightness.
HSCSD	High Speed Circuit Switched Data	a circuit-linked technology for higher transmission speeds -- up to 57 kilobits per second -- primarily in GSM systems.
HSD	High Speed Data	Interface normally using V.35 or EIA53 standards.
HSDPA	High-Speed Downlink Packet Access	also called 3.5G, a packet-based data service in W-CDMA downlink with data transmission up to 8-10 Mbit/s (and 20 Mbit/s for MIMO systems) over a 5MHz bandwidth in WCDMA downlink.
HSF	Heat Sink Fan High Sierra Format	This is a combination of a fan blowing air across the fins of a heatsink, usually on a high horsepower microprocessor. A logical format and file structure for CD-ROMs that paved the way for ISO 9660. As the industry began to evolve many different proprietary CD-ROM formats, the need for a common standard became obvious.
HSIL	Host Side Igmp Library	Cisco term
HSM	Hardware Security Module Hierarchical storage management	Generate and/or store secrets for use in crytography, commonly used in card payment systems The automated migration of data objects among storage devices, usually based on inactivity. By accepting lower access performance (higher access times), one can store objects less expensively.
HSO	Hot Spot Operator	A company that sets up and operates commercial hot spots in cafes, airports, hotels, train stations, convention centers and office buildings. An HSO typically installs one or more access points and an access control device along with a high speed Internet connection to the location.
HSR	Horizontal Scan Rate	The number of scan lines displayed per second on a computer monitor, expressed in kHz.
HSRP	Hot Standby Router Protocol	Provides high network availability and transparent network topology changes. HSRP creates a Hot Standby router group with a lead router that services all packets sent to the Hot Standby address. The lead router is monitored by other routers in the group, and if it fails, one of these standby routers inherits the lead position and the Hot Standby group address.
HSS	Home Subscriber Service	a key component in the IP Multimedia Subsystem (IMS), refers to a system including the master user database and software that supports IMS network entities that handle calls and sessions.
HSSDC	High Speed Serial Direct Connect	A type of connector used on Fibre Channel optical cables.
HSSI	High Speed Serial Interface	Standard for a serial interface at high speeds (64 Kbps and higher up to 52 Mbps) between DTE and DCE equipment over very short distances. Used for a physical connection between a router and a DSU.
HSUPA	High-Speed Uplink Packet Access	part of the specifications for 3GPP Release 6. It improves upstream data bit rates on 3G systems and complements High-Speed Downlink Packet Access (HSDPA), theoretically up to a maximum 5.8 Mbps uplink data rate at the cell level.
HT	Hyper-Threading HyperTransport	Intel technology with which a single processor can function as two virtual processors and execute two threads simultaneously. AMD Technology is a high-speed, low latency, point-to-point link designed to increase the communication speed between integrated circuits in computers, servers and embedded systems up to 48 times faster
HTC	formerly High Tech Computer Corporation	a Taiwan-based manufacturer of smartphones http://www.htc.com/
HTML or HTM	HyperText Markup Language	The coding language used to create Hypertext documents for use on the world wide web. HTML looks a lot like old-fashioned typesetting code, where you surround a block of text with codes that indicate how it should appear. Additionally, in HTML you can specify that a block of text, or a word, is linked to another file on the Internet.
HTML5	HyperText Markup Language 5	a whole set of new elements that make it much easier to structure pages, which commenced in 2004, is currently being carried out in a joint effort between the W3C HTML WG and the WHATWG.
HTT	Hyper-Threading Technology	Implementation of simultaneous multithreading on Intel Pentium 4, Mobile Pentium 4, and Xeon processors
HTTP	HyperText Transport Protocol	The protocol for moving hypertext files across the internet. Requires a HTTP client program on one end, and an HTTP server program on the other end. HTTP is the most important protocol used in the world wide web (WWW).
HTTPS	Secured HTTP or HTTP Secure	An Internet protocol that is used by Web servers and Web browsers to transfer and display hypermedia documents securely across the Internet.
HTTPS	HTTP over SSL	A Web protocol for secure transactions that encrypts and decrypts user page requests and pages returned by the Web server.
HUD	Head Up Display	A display that is usually projected to a position where the user only has to look up to see.
HURSE	Hasp Unit Record SErvice	IBM term. To get a punch or print of your cards
HWS	high watermark setup	A method to allocate a minimum number of unique device types that fulfill the requirements for each job step. Devices used in one step can be released and used again in later steps.
HXRC	Hitachi Extended Remote Copy	A remote-copy function for Hitachi Data Systems storage products. HXRC uses an asynchronous copy approach to deliver high data integrity with minimal disruption and performance impact to the primary system.
Hz	hertz	A unit of frequency equal to one cycle per second.
	H.x	A series of computing standards from the ITU. e.g. H.323: a standard in 1996 to promote compatibility in videoconference transmissions over IP networks.
	Hack / hacker	Term used to describe the unauthorised access of a computer as a means to gain information that the hacker is not entitled to or to access services and facilities for malicious purposes. Originally used to describe a computer enthusiast who pushed a system to its highest performance through clever programming. More commonly it is becoming synonymous with 'cracker' which is used to describe people who break into secured computer systems. An expert programmer who likes to spend a lot of time figuring out the finer details of computer systems or networks, as opposed to those who learn only the minimum necessary.
	Handshake	Exchange of predetermined signals between two devices establishing a connection.
	Halo	A light line around object edges in an image, produced by the USM (sharpening) technique.
	hard-coded	Referring to instructions that are written directly into a program and therefore cannot be easily modified, rather than instructions that can be modified by a user.
	Hardening	Hardening is the process of identifying and fixing vulnerabilities on a system.
	Haptic	Haptic is the science and physiology of the sense of touch. more...
	hash	A scrambled, or encrypted, form of a password or other text.
	header	A formatting style designated in HTML by a specific tag and used to set titles and subtitles apart from plain text.
	heat sink	A metal plate on some processors that helps dissipate heat.
	Heuristics	Heuristics means 'rule based'. Normally, for an Anti-Virus product to detect a virus, the virus must have been seen before, analyzed and detection added to the signature update files.
	hex dump	a hexadecimal view of computer data, from RAM or from a file or storage device.
	hi5	hi5 is a social networking website based in San Francisco, California. http://hi5.com/
	hit	As used in reference to the world wide web, hit means a single request from a web browser for a single item from a web server
	honeypot	a trap for people who tamper with computers maliciously through the Internet, just as a pot of honey traps flies.
	host	Any computer on a network that is a repository for services available to other computers on the network. The ISP's computer complex. The host process members' requests and keeps track of members' online experience.
	hot potato routing	A form of routing in which the nodes of a network have no buffer to store packets in before they are moved on to their final predetermined destination.
	Hot Swap	A hot swap is the replacement of a hard drive, CD-ROM drive, power supply, or other device with a similar device while the computer system using it remains in operation. The replacement can be because of a device failure or, for storage devices, to substitute other data.
	Hotmail	Windows Live Hotmail, formerly known as MSN Hotmail and commonly referred to simply as Hotmail, is a free web-based email service operated by Microsoft. http://www.hotmail.com/
	hotspot	A wireless Internet connection available for public use. Beyond mere convenience, hotspots offer broadband Internet access with connection speeds similar to cable and DSL. While some hotspots charge for access, more and more are opening their networks for free.
	hourglass	In computing, especially by means of the Windows operating system, an icon that replaces the pointer when the computer is performing a function and cannot receive new input.
	hub	Generally, a term used to describe a device that serves as the center of a star-topology network.
	Human Augmentation	sometimes referred to as "Human 2.0", creating cognitive and physical improvements as an integral part of the human body.
	hunting	Automatic routing of calls to an idle circuit in a prearranged group when the circuit called is busy. The movement of a call as it progresses through a group of lines.
	Hybrid network	A hybrid network is one that doesn't just rely on a singly type of bearer or leased line.
	Hype Cycle	A Gartner model designed to help clients make intelligent decisions about when to implement emerging technologies.
	Hypertext	Generally, any text that contains links to other documents - words or phrases in the document that can be chosen by a reader and which cause another document to be retrieved and displayed.
	hypervisor	a form of control software layer that enables multiple operating systems to run on the same physical hardware. The oldest hypervisor is IBM's VM — but this only runs on S/370-style hardware (where it hosted MVS, VSE, and other operating systems).