Dictionary of Computing - 5th Edition

operating system. In many GUIs, such as Microsoft Windows and the Apple Mac System, you can control all the functions of the operating system just using the mouse. Icons represent programs and files; instead of entering the file name, you select it by moving a pointer with a mouse.

guide bar / a d bɑ / noun a special line in a bar code that shows either the start or the finish of the code The standard guide bars are two thin lines that are a little longer than the coding lines.

gulp / lp/ noun a group of words, usually two bytes. byte, nybble

gun / n/ noun same as electron gun

COMMENT: Black and white monitors have a single beam gun, while colour monitors contain three, one for each primary colour (red, green and blue) used.

gutter / tə/ noun (in a DTP system) a blank space or inner margin between two facing pages

H abbr hex

H.323, H.324 noun standards that define how a video conferencing call is set up and managed over a communications link hack /h k/ verb 1. to experiment and explore computer software and hardware 2. to break into a computer system for criminal purposes

hacker / h kə/ noun a person who hacks

‘The two were also charged with offences under the Computer Misuse Act and found guilty of the very actions upon which every hacker is intent.’ [Comput-

ing]

hairline rule / heə la n ru l/ noun (in a DTP system) a very thin line

half adder /hɑ f də/ noun a binary addition circuit which can produce the sum of two inputs and a carry output if necessary, but will not accept a carry input half card / hɑ f kɑ d/ noun an expansion card that is half full length

half duplex /hɑ f dju pleks/ noun full form of HD

half-duplex modem / hɑ f dju pleksməυdem/ noun a modem which works in

one mode at a time, either transmitting or receiving Some modems can operate in half-duplex mode if required. half-height drive / hɑ f ha t dra v/ noun a disk drive whose front is half the height of a standard drive. Half-height

drives, usually 5.25 inches, are now the

norm on PCs.

half-intensity /hɑ f n tens ti/ adjective referring to a character or graphics display at half the usual display brightness halftone / hɑ f təυn/ noun a photograph or image that originally had continuous tones, displayed or printed by a computer using groups of dots to represent the tones

half word / hɑ f w d/ noun a sequence of bits occupying half a standard computer word, but which can be accessed as a single unit

hall effect /hɔ l fekt/ noun a description of the effect of a magnetic field on

electron flow

hall effect switch / hɔ l fekt sw tʃ/ noun a solid state electronic switch operated by a magnetic field

halt /hɔ lt/ noun a computer instruction to stop a CPU carrying out any further instructions until restarted, or until the program is restarted, usually by external

means, e.g. a reset button

halt condition /hɔ lt kən d ʃ(ə)n/ noun the operating state reached when a CPU comes across a fault or faulty instruction or halt instruction in the program that

is being run

halt instruction /hɔ lt n str kʃən/ noun a program instruction that causes a

CPU to halt, suspending operations, usually until it is reset

Hamming code / h m ŋ kəυd/ noun a coding system that uses check bits and checksums to detect and correct errors in transmitted data, mainly used in teletext systems

Hamming distance / h m ŋ

d stəns/ noun the number of digits that are different in two equal length words

hand-held computer / h nd held

kəm pju tə/, hand-held programmable

/ h nd held prəυ r məb(ə)l/ noun a very small computer which can be held in the hand, useful for basic information input, when a terminal is not available

hand-held scanner / h nd heldsk nə/ noun a device that is held in your hand and contains a row of photo-electric cells which, when moved over an image, convert it into data which can be manipulated by a computer

H & J / e tʃ ənd d'e / noun the process of justifying lines to a set width, splitting the long words correctly at the end of each line. Full form hyphenation and justification

handle / h nd(ə)l/ noun 1. (in programming) number used to identify an active file within the program that is accessing the file 2. (in a GUI) a small square displayed that can be dragged to change the shape of a window or graphical object

To stretch the box in the DTP program, select it once to display the handles then drag one handle to change its shape. handler / h ndlə/ noun a part of an operating system software or a special software routine which controls a device or function The scanner handler routines are supplied on disk. driver handshake / h n(d) ʃe k/, handshaking noun a set of standardised signals between two devices to make sure that the system is working correctly, the equipment is compatible and data transfer is correct (NOTE: Signals would include ready to receive, ready to transmit and data OK.)

handshake I/O control / h n(d)ʃe k a əυ kən trəυl/ noun the use of hand-

shake signals meaning ready-to-send and ready-to-receive, that allow a computer to communicate with a slower peripheral

hands off / h ndz ɒf/ noun referring to a working system in which the operator

does not control the operation, which is automatic

hands on / h ndz ɒn/ adjective referring to a working system in which the operator controls the operations by keying instructions on the keyboard The sales representatives have received hands-on experience of the new computer.

handwriting recognition

/ h ndra t ŋ rekə n ʃ(ə)n/ noun software that is capable of recognising handwritten text and converting it into ASCII characters The new PDA has excellent handwriting recognition.

hang /h ŋ/ verb to enter an endless loop and not respond to further instruction

(NOTE: hung)

hangover / h ŋəυvə/ noun a sudden tone change on a document that is transmitted over a fax machine as a gradual change, caused by equipment faults hangup / h ŋ p/ noun a sudden stop of a working program, often caused by the CPU executing an illegal instruction or entering an endless loop

hard /hɑ d/ adjective referring to parts of a computer system that cannot be pro-

grammed or altered

hard card / hɑ d kɑ d/ noun a board containing a hard disk drive and the required interfacing electronics, which can be slotted into a system’s expansion connector

hard copy /hɑ d kɒpi/ noun a printed document or copy of information contained in a computer or system, in a form that is readable. Also called soft copy

hard copy interface / hɑ d kɒpintəfe s/ noun a serial or parallel inter-

face used to transmit data between a com-

puter and a printer

hard disk /hɑ d d sk/ noun a rigid magnetic disk that is able to store many times more data than a floppy disk, and usually cannot be removed from the disk

drive

hard disk drive / hɑ d d sk dra v/ noun a unit used to store and retrieve data from a spinning hard disk on the commands of a computer. Abbr HDD. Also

called hard drive

hard drive / hɑ d dra v/ noun same as

hard disk drive

hard error /hɑ d erə/ noun an error which is permanent in a system

hard failure /hɑ d fe ljə/ noun a fault in hardware that must be mended before a

device will function correctly The hard failure was due to a burnt-out chip. hard reset /hɑ d ri set/ noun a switch that generates an electrical signal to reset the CPU and all devices, equivalent to turning a computer off and back on again hard return /hɑ d r t n/ noun a code in a word-processing document that indicates the end of a paragraph or its characteristics

hardware / hɑ d weə/ noun the physical units, components, integrated circuits, disks and mechanisms that make up a computer or its peripherals

‘Seuqent’s Platform division will focus on hardware and software manufacture, procurement and marketing, with the Enterprise division concentrating on services and client-server implementation.’ [Computing]

hardware compatibility / hɑ dweə kəm p tə b l ti/ noun architecture of two different computers that allows one to run the programs of the other without changing any device drivers or memory locations, or the ability of one to use the addon boards of the other

hardware configuration / hɑ dweə kən f jə re ʃ(ə)n/ noun a way in which

the hardware of a computer system is connected together

hardware dependent / hɑ dweə dpendənt/ adjective which will only work

with a particular model or brand of hardware The communications software is hardware dependent and will only work with Hayes-compatible modems. hardware failure / hɑ dweə fe ljə/ noun a fault with a hardware device or hardware that has stopped working properly

hardware graphics cursor

/ hɑ dweə r f ks k sə/ noun an electronic component that is used to calculate the position on screen of a pointer, according to the movement of a mouse, and display the pointer

hardware interrupt / hɑ dweəntər pt/ noun an interrupt signal generated by a piece of hardware rather than by software

hardware platform / hɑ dweəpl tfɔ m/ noun the standard of a particular computer such as IBM PC or Apple Mac

hardware reliability / hɑ dweə r la ə

b l ti/ noun the ability of a piece of hard-

ware to function normally over a period of time

hardware reset / hɑ dweə ri set/ noun a switch that generates an electrical signal to reset the CPU and all devices, equivalent to turning a computer off and back on again

hardware security / hɑ dweə skjυər ti/ noun the use of hardware such

as keys or cards to make a system secure hardwired connection / hɑ dwa əd kə nekʃ(ə)n/ noun a permanent phone line connection, rather than a plug and socket

hardwired logic / hɑ dwa əd lɒd' k/ noun a logical function or software program built using electronic hardware, using electronic devices such as logic components, rather than written in software hardwired program / hɑ dwa ədprəυ r m/ noun a computer program built into the hardware, and unable to be changed

harmonics /hɑ mɒn ks/ noun the integer multiple of a given sound frequency hartley / hɑ tli/ noun a unit of information equal to 3.32 bits, or the probability of one state out of ten equally probable states hash /h ʃ/ noun same as hashmark verb to produce a unique number derived from the entry itself, for each entry in a database

hash code / h ʃ kəυd/ noun a coding system derived from the ASCII codes, in which the code numbers for the first three letters are added up, giving a new number used as a hash code

hash-code system / h ʃ kəυds stəm/ noun a coding system using hash codes

hash index /h ʃ ndeks/ noun a list of entries according to their hashed numbers hashing function /h ʃ ŋ f ŋkʃən/ noun an algorithm used to produce a hash code for an entry and ensure that it is different from every other entry

hashmark / h ʃmɑ k/, hash mark

/ h ʃ mɑ k/ noun a printed sign ( # ) used as a hard copy marker or as an indicator. Also called hash

COMMENT: The US term is pound sign. In US usage # means number; #32 = number 32 (e.g. apartment number in a postal address,

paragraph number in a text).

hash table /h ʃ te b(ə)l/ noun a list of all entries in a file with their hashed key address

hash total /h ʃ təυt(ə)l/ noun a total of a number of hashed entries, used for error detection

hash value /h ʃ v lju / noun a number arrived at after a key is hashed

Hayes AT command set / he z e ti kə mɑ nd set/ noun a set of commands to

control a modem prefixed with the letters AT

Hayes-compatible / he z kəmp t b(ə)l/ adjective referring to a modem that is compatible with the Hayes AT command set

Hayes Corporation / he zkɔ pəre ʃ(ə)n/ a modem manufacturer that developed standard control language for modems

hazard / h zəd/ noun a fault in hardware due to incorrect signal timing

hazard-free implementation

/ h zəd fri mpl men te ʃ(ə)n/ noun a logical function design that has taken into account any hazards that could occur, and solved them

haze /he z/ noun same as fogging

HCI abbr host controller interface

HD / e tʃ di / noun data transmission in one direction only, over a bidirectional channel. Full form half duplex

HDD abbr hard disk drive

HDLC abbr high-level data link control HDTV abbr high definition television HDX abbr half duplex

head /hed/ noun 1. data that indicates the start address of a list of items stored in memory 2. a top edge of a book or of a page 3. the start of a reel of recording tape 4. the top part of a device, network or body

verb to be the first item of data in a list

The queue was headed by my file. head alignment /hed ə la nmənt/

noun 1. the correct position of a tape or disk head in relation to the magnetic surface, to give the best performance and correct track location 2. the location of the read head in the same position as the write head was, in relation to the magnetic medium

head cleaning disk / hed kli n ŋ d sk/ noun a special disk which is used to clean the disk read/write heads

head crash / hed kr ʃ/ noun a component failure in a disk drive, in which the head is allowed to hit the surface of the spinning disk, causing disk surface damage and data corruption

head demagnetiser / hed dim nəta zə/ noun a device used to re-

move any stray magnetic effects that might have built up on the tape head

head end / hed end/ noun interconnection equipment between an antenna and a cable television network

header / hedə/ noun 1. (in a local area network) a packet of data that is sent before a transmission to provide information on destination and routing 2. information at the beginning of a list of data relating to the rest of the data 3. a section of words at the top of a page of a document, giving e.g. the title, author’s name or page number. Also called heading. footer

header block / hedə blɒk/ noun a block of data at the beginning of a file containing data about file characteristics header card / hedə kɑ d/ noun a punched card containing information about the rest of the cards in the set header label / hedə le b(ə)l/ noun a section of data at the beginning of a magnetic tape, that contains identification, format and control information

head gap / hed p/ noun same as air gap

heading / hed ŋ/ noun 1. the title or name of a document or file 2. a header or section of words at the top of each page of a document. Also called headline headlife / hedla f/ noun the length of time that a video or tape head can work before being serviced or replaced headline / hedla n/ noun same as heading

head of form / hed əv fɔ m/ noun the first line on a form or sheet of paper that can be printed on

head park / hed pɑ k/ noun the process of moving the read/write head in a hard disk drive to a safe position, not over the disk, so that if the unit is knocked or jarred the head will not damage the disk surface head positioning /hed pə z ʃ(ə)n ŋ/ noun the process of moving the read/write head to the correct track on a disk

head wheel / hed wi l/ noun a wheel that keeps video tape in contact with the head

heap /hi p/ noun 1. a temporary data storage area that allows random access. Compare stack 2. a binary tree heat-sensitive paper / hi t sens t vpe pə/ noun electrostatic printer

heat-sink /hi t s ŋk/ noun a metal device used to conduct heat away from an electronic component to prevent damage helical scan / hel k(ə)l sk n/ noun a method of storing data on magnetic tape in which the write head stores data in diagonal strips rather than parallel with the tape edge so using the tape area more efficiently and allowing more data to be recorded. It is used most often in video tape recorders.

help /help/ noun a function in a program or system that provides useful information about the program in use Hit the HELP key if you want information about what to do next.

COMMENT: Most software applications for IBM PCs have standardised the use of the F1 function key to display help text explaining how something can be done.

help desk / help desk/ noun a service that provides technical help and support for people using a computer package or network

helper application / helpəpl ke ʃ(ə)n/ noun software which works with a web browser to increase the functionality of the browser To view Adobe Acrobat pages in your web browser you will need to get the Adobe helper application.

help key / help ki / noun a key that displays help information, on an Apple Mac a special key, on an IBM PC the F1 function key

help screen / help skri n/ noun a display of information about a program or function

hertz /h ts/ noun an SI unit of frequency, defined as the number of cycles per second of time. Abbr Hz

COMMENT: Hertz rate is the frequency at which mains electricity is supplied to the consumer. The hertz rate in the USA and Canada is 60; in Europe it is 50.

heterogeneous multiplexing

/ hetərəυd'i niəs m lt pleks ŋ/ noun a communications multiplexing system that can deal with channels with different transmission rates and protocols

heterogeneous network

/ hetərəυd'i niəs netw k/ noun a computer network joining computers of many different types and makes heuristic /hjυə r st k/ adjective which learns from past experiences A heuristic program learns from its previous actions and decisions.

Hewlett Packard / hewlət p kɑ d/ manufacturer of computers, test equipment and printers. Abbr HP

Hewlett Packard Graphics Language / hewlət p kɑ d r f ks

l ŋ w d'/ a standard set of commands used to describe graphics. Abbr HPGL

Hewlett Packard Interface Bus

/ hewlət p kɑ d ntəfe s b s/ a standard method of interfacing peripheral devices or test equipment and computers. Abbr HPIB

Hewlett Packard LaserJet / hewlətp kɑ d le zəd'et/ a trade name for a la-

ser printer manufactured by Hewlett Packard that uses its PCL language to describe a page. Also called LaserJet

Hewlett Packard Printer Control Language / hewlət p kɑ d pr ntə kən trəυl l ŋ w d'/ a standard set of

commands developed by Hewlett Packard to allow a software application to control a

laser printer’s functions. Abbr HP-PCL hex /heksə des m(ə)l nəυ te ʃ(ə)n/,

hexadecimal notation noun a number system using base 16 and the digits 0–9

and A-F. Abbr H

hex dump / heks d mp/ noun the display of a section of memory in hexadeci-

mal form

hex keypad /heks ki p d/ noun a keypad with 16 keys, 0–9 and A-F, for all the hexadecimal digits

HFS / e tʃ ef es/ noun (in an Apple Mac system) a method used to store and organise files on a disk. Full form hierarchical

filing system

hidden files / h d(ə)n fa lz/ plural noun important system files which are not displayed in a directory listing and cannot normally be read by a user It allows users to backup or restore hidden files independently.

hidden line algorithm / h d(ə)n la nl ər ð(ə)m/ noun a mathematical formula that removes hidden lines from a two-dimensional computer image of a 3-D

object

hidden line removal / h d(ə)n la n rmu vəl/ noun the erasure of lines which should not be visible when looking at a two-dimensional image of a three-dimen-

sional object

hidden lines / h d(ə)n la nz/ plural noun lines which make up a three-dimen- sional object, but are obscured when displayed as a two-dimensional image

hierarchical /ha ə rɑ k k(ə)l/ adjective referring to a way of organising data or objects or structures with the most important or highest priority item at the top, then working down a tree structure

hierarchical communications system / ha ərɑ k k(ə)l kə mju nke ʃ(ə)nz s stəm/ noun a network in

which each branch has a number of separate minor branches dividing from it

hierarchical computer network

/ ha ərɑ k k(ə)l kəm pju tə netw k/ noun a method of allocating control and processing functions in a network to the computers which are most suited to the task

hierarchical database

/ ha ərɑ k k(ə)l de təbe s/ noun a database in which records can be related to each other in a defined structure

hierarchical directory

/ ha ərɑ k k(ə)l da rekt(ə)ri/ noun a directory listing of files on a disk, showing the main directory and its files, branches and any sub-directories

hierarchical filing system

/ ha ərɑ k k(ə)l fa l ŋ s stəm/ noun full form of HFS

hierarchical routing / ha ərɑ k k(ə)lru t ŋ/ noun a method of directing network traffic over a complex network by breaking down the structure of the network into separate levels, each level being responsible for directing traffic within its area The Internet has a three-level hierarchical routing system in which the backbones can direct traffic from one Mid-level to another, the mid-levels can direct traffic from one server site to another and each server site can direct traffic internally.

hierarchical vector quantisation

/ ha ərɑ k k(ə)l vektəkwɒnta ze ʃ(ə)n/ noun full form of

HVQ

hierarchy / ha ərɑ ki/ noun a way in which objects or data or structures are organised, usually with the most important or highest priority or most general item at the top, then working down a tree structure

high definition television / hadef n ʃ(ə)n tel v '(ə)n/ noun a broad-

cast television standard that displays images at a different aspect ratio and with much better definition than existing television sets. Abbr HDTV (NOTE: There are six standards: all display 16:9 aspect ratio images, three support a resolution of

1920x1080 pixels, three support

1280x720.)

high density storage / ha densstɔ r d'ti/ noun a very large number of

bits stored per area of storage medium

high-end / ha end/ adjective referring to expensive or high-performance devices high fidelity /ha f deləti/ noun very good quality sound, usually stereo sound recorded in 16 bits at a sample rate of 44.1 KHz

high-level data link control /halev(ə)l de tə l ŋk kən trəυl/ noun an

ISO standard that provides a link-layer protocol and defines how data is formatted before being transmitted over a synchronous network. Abbr HLDLC

high-level data link control station

/ ha lev(ə)l de tə l ŋk kən trəυlste ʃ(ə)n/ noun equipment and programs which correctly receive and transmit standard HLDLC data frames high-level language /ha lev(ə)l/, high-level programming language noun a computer programming language which is easy to learn and allows the user to write programs using words and commands that are easy to understand and look like English words. Abbr HLL (NOTE: The program is then translated into machine code, with one HLL instruction often representing more than one machine code instruction.)

highlight / ha la t/ noun a character or set of symbols treated so as to stand out from the rest of the text, often by using bold type verb to make part of the text stand out from the rest The headings are highlighted in bold.

highlight bar / ha la t bɑ / noun (in a display) a line that can be moved up and down by a user that indicates which option is selected from a menu or list of options

Move the highlight bar down to the third menu option and press Return.

high memory /ha mem(ə)ri/ noun (in an IBM PC) a memory area between 640 Kb and 1 Mb

high memory area / ha mem(ə)rieəriə/ noun (in an IBM PC) the first 64

Kb of extended memory above 1 Mb that can be used by MS-DOS programs. Abbr

HMA

high order /ha ɔ də/ noun a digit with the greatest weighting within a number

high performance filing system

/ ha pə fɔ məns fa l ŋ s stəm/ noun full form of HPFS

high priority program / ha praɒr ti prəυ r m/ noun a program that is

important or urgent and is processed before others

high-resolution /ha rezə lu ʃ(ə)n/, high-res noun the ability to display or detect a very large number of pixels per unit area. Also called hi-res

high resolution graphics / harezəlu ʃ(ə)n r f ks/ noun full form of

HRG

High Sierra / ha si erə/ noun an early CD-ROM standard that then became the ISO 9660 standard (NOTE: It was named

after an area near Lake Tahoe, USA.) high-spec /ha spek/ plural noun having a high specification High-spec cabling needs to be very carefully handled. high specification /ha spes fke ʃ(ə)n/ noun a high degree of accuracy or a large number of features high-speed / ha spi d/ adjective which operates faster than normal data transmission or processing

high-speed carry / ha spi d k ri/ noun a single operation in which a carry into an adder results in a carry out

high-speed serial interface /ha spi d s əriəl ntəfe s/ noun full form of

HSSI

high-speed skip / ha spi d sk p/ noun a rapid movement of paper in a printer, ignoring the normal line advance high-tech /ha tek/ adjective technologically advanced

highway / ha we / noun same as bus hill climbing /h l kla m ŋ/ noun a method of achieving a goal in an IKBS

hi-res /ha re z/ noun same as high-res- olution

histogram / h stə r m/ noun a graph on which values are represented as vertical or horizontal bars

history / h st(ə)ri/ noun a feature of some applications that keeps a log of the actions a user has carried out, the places within a hypertext document visited or the sites on the Internet explored

hit /h t/ noun a successful match or search of a database There was a hit after just a few seconds. hit on the line a short period of noise on a communications line, causing data corruption verb to

press a key To save the text, hit ESCAPE S. (NOTE: hitting – hit)

hit point / h t pɔ nt/ noun an important action or piece of information displayed in a presentation

HLDLC abbr high-level data link control HLL abbr high-level language

HLS abbr hue, lightness, saturation HMA abbr high memory area HMI abbr human-machine interface

HOF abbr head of form

hold /həυld/ noun synchronisation timing pulse for a television time base signalverb to retain or keep a value or communications line or section of memory (NOTE: held)

COMMENT: The hold feature keeps the picture steady and central on the screen. Some televisions have horizontal and vertical hold controls to allow the picture to be moved and set

up according to various conditions.

holding loop / həυld ŋ lu p/ noun a section of program that loops until it is broken by some action, most often used when waiting for a response from the key-

board or a device

holding time / həυld ŋ ta m/ noun the time spent by a communications circuit on call

holdup / hɒld p/ noun 1. a time period over which power will be supplied by a UPS 2. a pause in a program or device due to a malfunction

hologram / hɒlə r m/ noun an imaginary three-dimensional image produced by the interference pattern when a part of a coherent light source, e.g. a laser, is reflected from an object and mixed with the main beam

holographic image / hɒlə r f km d'/ noun a hologram of a three-di- mensional object

holographic storage / hɒlə r f kstɔ r d'/ noun storage of data as a holo-

graphic image which is then read by a bank of photocells and a laser (NOTE: This is a storage medium with massive storage potential.)

home /həυm/ noun a starting point or the

initial point

home banking /həυm b ŋk ŋ/ noun a method of examining and carrying out bank transactions in the user’s home via a

terminal and modem

home computer /həυm kəm pju tə/ noun a microcomputer designed for home use, whose applications might include

teaching, games, personal finance and word-processing

home key / həυm ki / noun a key on an IBM PC keyboard that moves the cursor to the beginning of a line of text

home page / həυm pe d'/ noun the opening page of a website The home page is formatted using HTML and stored in a file called index.html.

home record /həυm rekɔ d/ noun the first or initial data record in a file

homogeneous computer network

/ həυməυd'i niəs kəm pju tənetw k/ noun a network made up of

similar machines that are compatible or from the same manufacturer

homogeneous multiplexing

/ həυməυd'i niəs m lt pleks ŋ/ noun a switching multiplexer system in which all the channels contain data using the same protocol and transmission rate hood /hυd/ noun a cover which protects something

hook /hυk/ noun a point in a program at which a programmer can insert test code or debugging code

hop /hɒp/ noun the path taken by a packet of data as it moves from one server or router to another

hop count / hɒp kaυnt/ noun the number of hops required to send information from one computer to another over the Internet

hopper / hɒpə/ noun a device which holds punched cards and feeds them into the reader

horizontal axis / hɒr zɒnt(ə)l ks s/ noun a reference line used for horizontal coordinates on a graph

horizontal blanking period

/ hɒr zɒnt(ə)l bl ŋk ŋ p əriəd/ noun the time taken for the picture beam in a monitor to return to the start of the next line from the end of the previous line horizontal check / hɒr zɒnt(ə)ltʃek/ noun an error detection method for transmitted data

horizontal scan frequency

/ hɒr zɒnt(ə)l sk n fri kwənsi/ noun the number of lines on a video display that are refreshed each second

horizontal scrollbar / hɒr zɒnt(ə)lskrəυlbɑ / noun (in a GUI) a bar along

the bottom of a window that indicates that the page is wider than the window (NOTE: A user can move horizontally across the

page by dragging the indicator bar on the

scrollbar.)

horizontal scrolling / hɒr zɒnt(ə)lskrəυl ŋ/ noun the process of moving

across a page, horizontally

horizontal wraparound

/ hɒr zɒnt(ə)l r pə raυnd/ noun the movement of a cursor on a computer display from the end of one line to the begin-

ning of the next

host /həυst/ noun, adjective to provide storage space on a server computer where a user can store files or data, often used to store the files required for a website We chose this company to host our website because it has reliable server computers and high-speed connection to the Internet.

‘…you select fonts manually or through commands sent from the host computer along with the text’

[Byte]

host adapter /həυst ə d ptə/ noun an adapter which connects to a host computer

The cable to connect the scanner to the

host adapter is included.

host address / həυst ə dres/ noun

same as Internet address

host computer /həυst kəm pju tə/ noun 1. the main controlling computer in a multi-user or distributed system 2. a computer used to write and debug software for another computer, often using a cross compiler 3. a computer in a network that provides special services or programming languages to all users

‘…you select fonts manually or through commands sent from the host computer along with the text’ [Byte]

hosting service provider / həυst ŋ

s v s prə va də/ noun same as host

service

host name / həυst ne m/ noun a name

given to a website on the Internet

host number / həυst n mbə/ noun

same as Internet address

host service / həυst s v s/ noun a company that provides connections to the Internet and storage space on its computers which can store the files for a user’s website We rent storage space on this host service provider’s server for our company website. ISP. Also called hosting service provider

hot chassis /hɒt ʃ si/ noun a metal framework or case around a computer that is connected to a voltage supply rather than being earthed

hot fix / hɒt f ks/ noun the process of detecting and repairing a fault, usually a

corrupt sector on a hard disk, without affecting normal operations

hot key / hɒt ki / noun a special key or key combination which starts a process or activates a program

hot link / hɒt l ŋk/ noun a command within a hypertext program that links a hotspot or hotword on one page with a second destination page which is displayed if the user selects the hotspot

hot plugging / hɒt pl ŋ/ noun a feature of a computer that allows a device or peripheral to be plugged in or connected while the computer is working This server support hot plugging so I can plug in this network card and the operating system software will automatically detect and alter its configuration. Also called hot

swapping

hotspot / hɒtspɒt/ noun a special area on an image or display that does something when the cursor is moved onto it

The image of the trumpet is a hotspot and will play a sound when you move the

pointer over it.

hot standby /hɒt st ndba / noun a piece of hardware that is kept operational at all times and is used as backup in case of system failure. Compare cold standby,

warm standby

hot swapping / hɒt swɒp ŋ/ noun same as hot plugging

hotword / hɒtw d/ noun a word within displayed text that does something when

the cursor is moved onto it or it is selected hot zone / hɒt zəυn/ noun a text area to

the left of the right margin in a word-proc- essed document where, if a word does not fit completely into the line, a hyphen is automatically inserted

housekeeping / haυs ki p ŋ/ noun tasks that have to be regularly carried out to maintain a computer system, e.g. checking backups and deleting unwanted files housekeeping routine / haυski p ŋ ru ti n/ noun a set of instructions executed once, at the start of a new program, to carry out system actions such as clear memory, configure function keys or change screen display mode

housing / haυz ŋ/ noun a solid case

The computer housing was damaged when

it fell on the floor.

howler / haυlə/ noun a buzzer which indicates to a telephone exchange operator that a user’s telephone handset is not on the receiver

HP abbr Hewlett Packard

HPFS / e tʃ pi ef es/ noun (in an OS/2 operating system) a method of storing file information that is faster and more flexible than MS-DOS FAT. Full form high performance filing system

HPGL abbr Hewlett Packard Graphics Language

HPIB abbr Hewlett Packard Interface Bus HP-PCL abbr Hewlett Packard Printer

Control Language

HRG / e tʃ ɑ d'i / noun the ability to display a large number of pixels per unit area. Full form high resolution graphics

HSB abbr hue, saturation and brightness

HSI abbr hue, saturation and intensity HSSI / e tʃ es es a / noun a serial link

that can transfer data at data rates up to 52 Mbits/second, used in some wide area network systems. Full form high-speed serial interface. USB

HSV abbr hue, saturation and value

HTML / e tʃ ti em el/ noun a series of special codes that define the typeface and style that should be used when displaying the text and also allow hypertext links to other parts of the document or to other documents HTML is used to create documents for the World Wide Web. Full form

hypertext markup language

HTTP / e tʃ ti ti pi / noun a series of commands used by a browser to ask an Internet web server for information about a webpage. Full form hypertext transfer

protocol

HTTPd / e tʃ ti ti pi di / noun a server software that carries sends webpage files to a client in response to a request from a user’s web browser When you type a website address into your web browser, this sends a request to the HTTPd server software that replies with the HTML code of a formatted webpage. Full form hypertext transfer protocol daemon

hub /h b/ noun 1. the central part of a disk, usually with a hole and ring which the disk drive grips to spin the disk 2. (in a star-topology network) the central ring or wiring cabinet where all circuits meet and form an electrical path for signals

hue /hju / noun the colour of an image or pixel

hue, saturation and intensity / hjus tʃəre ʃ(ə)n ənd n tens ti/ noun a

method of defining a colour through its

three properties. Abbr HSI. Also called hue, saturation and brightness, hue saturation and level (NOTE: Hue is colour defined by its the wavelength; saturation refers to the purity of the colour (where at zero saturation the colour appears white and full saturation is pure colour); and intensity, brightness and level refer to the amount of white.)

hue, saturation and value / hjus tʃəre ʃ(ə)n ənd v lju / noun same

as hue, saturation and intensity. abbr

HSV

Huffman code / h fmən kəυd/ noun a data compression code in which frequent characters occupy less bit space than less frequent ones

human-computer interface noun abbr HMI

hung hang

hunting / h nt ŋ/ noun the process of searching out a data record in a file

HVQ / e tʃ vi kju / noun a video compression standard which allows colour video images to be transmitted in a bandwidth of 112 Kbps. Full form hierarchical vector quantisation

hybrid circuit / ha br d s k t/ noun the connection of a number of different electronic components such as integrated circuits, transistors, resistors and capacitors in a small package, which since the components are not contained in their own protective packages, requires far less space than the individual discrete components hybrid computer / ha br d kəmpju tə/ noun a combination of analog and digital circuits in a computer system to achieve a particular goal

hybrid interface / ha br d ntəfe s/ noun a one-off interface between a computer and a piece of analog equipment hybrid system / ha br d s stəm/ noun a combination of analog and digital computers and equipment to provide an optimal system for a particular task HyperCard / ha pəkɑ d/ a trade name for a database system controlled by HyperTalk programming language, used to produce hypertext documents

hyperlink / ha pəl ŋk/ noun a word or image or button in a webpage or multime-

dia title that moves the user to another page when clicked

hypermedia / ha pəmi diə/ noun a hypertext system that is capable of displaying images and sound

HyperTalk / ha pətɔ k/ a trade name for a programming language used to control a HyperCard database

HyperTerminal / ha pə t m n(ə)l/ noun a communications program that is included with Windows 95 and allows a user to call a remote computer via a modem and transfer files

hypertext / ha pətekst/ noun 1. a multimedia system of organising information in which certain words in a document link to other documents and display the text when the word is selected In this hypertext page, click once on the word ‘computer’ and it will tell you what a computer is.

2. a way of linking one word or image on an Internet page to another page in which clicking on certain words or images moves the user directly to the relevant new page

hypertext markup language

/ ha pətekst mɑ k p l ŋ w d'/ noun full form of HTML

hypertext transfer protocol

/ ha pətekst tr nsf prəυtəkɒl/ noun full form of HTTP

hypertext transfer protocol daemon / ha pətekst tr nsf prəυtəkɒldi mən/ noun full form of HTTPd

hyphenated / ha fəne t d/ adjective written with a hyphen The word ‘highlevel’ is usually hyphenated. hyphenate justify / ha fəne td' st fa / verb to break long words correctly where they split at the ends of lines. Some programs will also automatically justify, so as to give a straight right margin.

(NOTE: hyphenates – hyphenating – hyphenated)

hyphenation / ha fə ne ʃ(ə)n/ noun the splitting of a word at the end of a line, when the word is too long to fit

hyphenation and justification

/ha fə na ʃ(ə)n ən d' st f ke ʃ(ə)n/ noun full form of H & J An American hyphenation and justification program will not work with British English spellings.

Hz abbr hertz