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

connet 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.

connet 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.

connet Host Controller Interface

connet Human-Computer Interaction

connet BlueTooth technology

connet 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

connet to A set of information on a diskette or tape that describes the contents of the diskette or tape.

connet to 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.

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.

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
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

connet High-Intensity Discharge

connet Human Interface Device

connet Light bulb technology used mainly in projectors

connet 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.

connet Hewlett-Packard

connet HoneyPot

connet 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

connet 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.

connet Heat Sink Fan

connet High Sierra Format

connet This is a combination of a fan blowing air across the fins of a heatsink, usually on a high horsepower microprocessor.

connet 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

connet Hardware Security Module

connet Hierarchical storage management

connet Generate and/or store secrets for use in crytography, commonly used in card payment systems

connet 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.

connet Hyper-Threading

connet HyperTransport

connet Intel technology with which a single processor can function as two virtual processors and execute two threads simultaneously.

connet 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/

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

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.


hertz A unit of frequency equal to one cycle per second.

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

connet 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.

connet 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.

connet 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.

connet Any computer on a network that is a repository for services available to other computers on the network.

connet 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.

connet Automatic routing of calls to an idle circuit in a prearranged group when the circuit called is busy.

connet 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).