iGCSE ICT Glossary: Key Terms and Definitions, Exams of Information and Communications Technology (ICT)

Download iGCSE ICT Glossary: Key Terms and Definitions and more Exams Information and Communications Technology (ICT) in PDF only on Docsity! iGCSE ICT Glossary iGCSE ICT Glossary Mega Study Guide Exam Questions with Certified Solutions 2024-2025. (Dark Back Ground for better Visibility and eye Care) 3D inkjet printer - Answer: An output device that produces solid 3D models using a modified inkjet printer and resins to replace inks. 1 iGCSE ICT Glossary abnormal data - Answer: Data that is of the wrong type (e.g. text in a numeric field) or is outside the accepted range (e.g. an exam mark percentage of 110). absolute referencing - Answer: Fixes a cell reference within a spreadsheet so that when the formula is copied this cell reference never changes. absolute value - Answer: Fixes a value so that it cannot change, for example in a webpage a table width can be set to 300 points. This table will always remain 300 points wide and will not change if the size of the browser window is changed. access point - Answer: Used in wireless networks to allow access to the network at various points using wireless technology (e.g. an airport will have several APs allowing 100 per cent coverage for users). actuator - Answer: A transducer which takes signals from a computer and converts them into some form of motion (e.g. motors, pumps, valves etc.). administrator - Answer: The person who is in control of a computer network. alphanumeric - Answer: A field type where any character is acceptable input - sometimes called text. analogue data - Answer: Data which represents physical constantly varying quantities such as time, temperature, etc. 2 iGCSE ICT Glossary automatic teller machine - Answer: A machine where customers can access their bank accounts using a card and PIN; usually used to withdraw cash from their account. AutoSum - Answer: A function within Microsoft Excel that adds together the contents of a number of cells. AVERAGE - Answer: A function within Microsoft Excel that calculates the mean (average) of a list of numbers. back up - Answer: A copy of a file/data on a different medium (e.g. disk, flash drive, CD, etc.) in case of problems with the internal hard disk drive. backing storage - Answer: Secondary storage device that allows a user to back up data from a computer system (e.g. CD, DVD, floppy disk, memory stick). bandwidth - Answer: This is a reference to the range of frequencies a communication channel can handle. The bigger the bandwidth the more data can be sent and received at the same time. The amount of data that can be communicated also relies upon the transfer rate. This is often used to describe Internet connection, with the term broadband meaning it has more than 3KHz (although in real terms at least 300MHz is needed in current systems). barcode - Answer: Optical machine-readable representation of data that uses thick and thin lines to represent numbers. 5 iGCSE ICT Glossary barcode reader - Answer: An input device that can read/scan barcodes using laser light. basic input/output system (BIOS) - Answer: Code used to tell computer what to do when it first starts up (sometimes referred to as the boot). batch processing - Answer: System where all the data is first gathered together before it is processed all in one go without further need of human intervention. It is used in billing systems and cheque processing, for example. behaviour layer - Answer: One of the 3 layers in webpage development. The behaviour layer is used to do 'an action' (rather than just display or link to other pages) and often uses script languages embedded into the HTML. There are many different script languages but the most common for web development are Javascript, PHP, Perl and CGI. BIOS - Answer: See basic input/output system bit - Answer: Short for binary digit and equal to a 1 or a 0; the fundamental memory unit. bit map - Answer: Representation, consisting of rows and columns of dots, of a graphical image in a computer. The density of the dots is called the resolution. In computer screens/monitors the dots are referred to as a pixels. 6 iGCSE ICT Glossary blogger - Answer: Someone who maintains a blog. blogs - Answer: Short for web log; a webpage which is accessed by the public, who can read or write messages. Bluetooth - Answer: Open wireless protocol over a short distance that allows devices to communicate using radio waves instead of wires. blu-ray disk - Answer: An optical disk with very large capacity (currently the largest of all the optical media) using laser light close to the blue/violet spectra, which permits much larger storage capacity. body - Answer: The section of HTML in a webpage that contains the contents (e.g. text, images, etc) and the tags describing the content, hyperlinks and structure (e.g. tables used to lay out the page) of a webpage. body text - Answer: The basic style of text within a document, commonly used for all of the paragraphs. bookmark - Answer: The address (URL) of a webpage saved by a user so that it can be revisited at some later date. Boolean data - Answer: Data that can have only two possible answers: true (1) or false (0). 7 iGCSE ICT Glossary cell padding - Answer: An HTML attribute used with the table tag to specify the space between the cell wall and the cell content. cell spacing - Answer: An HTML attribute used with the table tag to specify the space between the cells. central processing unit - Answer: The part of the computer that interprets and executes commands from computer hardware and software. changeover - Answer: A stage in systems analysis where the new system is introduced by one of four methods: direct, parallel, pilot or phased changeover. check digit - Answer: An extra digit added to a number (often at the end) which is used to check for errors during transmission/reading of the number, e.g. in barcodes. chip and PIN - Answer: A technology that is used in debit and credit cards for payment in stores or use with ATMS. The chip is read by a card reader machine and compares it with the number typed in by the customer. It helps to ensures security of transactions. chip and PIN readers - Answer: A technology that is used with credit/debit/loyalty cards which contain a chip as well as a magnetic stripe. These are used at EFTPOS terminals, where the customer enters their PIN using a keypad and this is compared with the number stored on the chip. 10 iGCSE ICT Glossary CLI - Answer: See command line interface clipboard - Answer: A temporary storage area used by the operating system to hold information that you cut or copy it, ready to be pasted at a later time. closed question - Answer: Is a question which has only specified answers like "yes" or "no", or a multiple choice question. Users are always restricted to the answers that they can give in a closed question. For example: "Do you like school? Answer Y or N". A similar open question is "How do you feel about school?" CMOS - Answer: See complementary metal oxide semiconductor colour depth - Answer: Is the number of bits used to store the colours in each pixel. It is sometimes called bit depth or bits per pixel (bpp). For example: If an image has 24bit colour depth tis would be displayed as 224 colours (about 16.7 million), which would only be visible on a computer with a 24 bit graphics card (video adapter) and suitable monitor. A 24 bit colour depth has 8 bits per channel (red, green, blue). comma separated values - Answer: A file format (.csv) used to hold tabular data, e.g. from a spreadsheet or database table. It stores it as a text-based file using commas (or semi-colons in some locations) to separate the data items. 11 iGCSE ICT Glossary command line interface - Answer: A user interface that requires a user to type in instructions, choose options from a menu, open software, etc. complementary metal oxide semiconductor - Answer: Type of semi-conductor chip that holds data (usually the BIOS) without the need for an external power source. concept keyboard - Answer: A type of keyboard where icons or phrases replace letters and numbers. content layer - Answer: One of the 3 layers in web page development. The content layer is used to define the structure of the webpage, often using tables or frames and the content of the pages including text or images and hyperlinks to other pages. The content layer is often written in html or xhtml. contiguous data - Answer: Data that is placed together and can be selected in a single range. contrast - Answer: Is the difference between the amount of colour (or greyscale) between two different features within an image. control system - Answer: A set of devices which manage, command or regulate the behaviour of other devices or systems. 12 iGCSE ICT Glossary cut and paste - Answer: To move a highlighted object by cutting the object and pasting the object into a new location. This holds another copy of the object in the clipboard for if it needs to be pasted again into another location. DAC - Answer: See digital to analogue converter data file - Answer: A collection of records where each record is made up of fields for the individual data items (e.g. name, address, etc.). data integrity - Answer: Refers to maintaining the validity of data which can be compromised in a number of ways, e.g. by data entry errors, viruses, hardware malfunctions, etc. The risks can be minimised by security systems, backing up data and by having interfaces with built-in error traps. data logger - Answer: A device that automatically captures data from its surroundings over a period of time. It usually uses sensors to gather the data, which is then stored on a computer for later analysis. data packet - Answer: The basic unit of communication over a digital network. database - Answer: A collection of information structured in some way to permit manipulation and searching of the data. date and time - Answer: A field type within Microsoft Access that is used to store dates and times. 15 iGCSE ICT Glossary decimal - Answer: A data type used within numeric fields in Microsoft Access to store the data in decimal format. deprecate - Answer: A deprecated markup command or attribute is one that is outdated and may not work with future web browsers. Deprecated commands should not be used in your markup. descender - Answer: The part of a lowercase letter (g, j, p, q or y), that falls below the baseline of the letters. desktop publisher - Answer: Software that allows text and graphics to be imported from other applications and then arranged and laid out for the production of a printed document. dial-up modem - Answer: A modem that uses the normal telephone network, dialling up the internet service provider whenever internet access is required. Unlike with a broadband modem, the system is not always on. It also ties up the telephone lines since it uses the same bandwidth as normal telephone signals. digital camera - Answer: Cameras that don't use film to record photographs. Light is picked up by sensors and the resultant image stored on a solid state memory in the camera. digital data - Answer: Discrete data (such as 0s and 1s). 16 iGCSE ICT Glossary digital to analogue converter - Answer: A device used to convert digital signals into analogue signals (so the computer can control another device such as a pump, motor, etc.). disk operating system - Answer: Type of operating system developed for PCs in the 1980s. domain name - Answer: Is the name given to the place we can find a particular website on the Internet. dongle - Answer: A form of memory stick used as a security device when using software, in order to reduce the risk of software piracy. DOS - Answer: See disk operating system download - Answer: To transfer a file from a central computer/server/internet to the user's computer/ workstation. DVD-R - Answer: Optical storage device that can be recorded on only once. DVD-RAM - Answer: Optical storage device that uses concentric tracks (rather than single spiral as used with normal CD and DVD) to record data. It can be written to and read from many times 17 iGCSE ICT Glossary expert system - Answer: A system that attempts to reproduce the ability of human experts in carrying out complex tasks such as medical diagnosis, etc. extreme data - Answer: Data which is on the boundaries of acceptable data; for example if people's ages can be in the range 18 to 65 then the values 18 and 65 are seen as extreme data. fax - Answer: Short for facsimile machine; used to send pages of text over the telephone network. feasibility study - Answer: Used to determine whether or not it is possible to proceed with a new system based on a number of arguments such as cost, constraints, etc. field - Answer: A place used to hold a single data item within a database. field codes - Answer: Individual information taken from the data source in a mail merged document. file - Answer: A logically organised collection of records, usually where all the records are organised so that they can be stored together within a database. file server - Answer: A computer that provides network computers/workstations with controlled access to shared resources. 20 iGCSE ICT Glossary finalise - Answer: The final stage in writing to a CD. It turns the CD into a CD-ROM and it is then impossible to write any more data on it. Finalising also allows the CD to played on other systems (e.g. home entertainment systems). firewall - Answer: A suite of software, located on a network gateway server, which protects the resources of a network or computer from users on another network. fixed hard disk drive - Answer: A memory device inside a computer which cannot be removed. It uses a hard disk to save programs, data, etc. flash memory cards - Answer: solid state memory used as memory cards in cameras and mobile phones, for example. flat file structure - Answer: All records in a database joined together to form one large file rather than using linked tables. flat-file database - Answer: A database structure using only one table footer - Answer: The area at the bottom of a document between the bottom of the page and the bottom margin. foreign key - Answer: Is the name given to a field in a table within a relational database, which is linked by a relationship to a primary key field in another table. 21 iGCSE ICT Glossary formula - Answer: A set of instructions used to perform a calculation in a spreadsheet. A formula can include cell references, numbers, mathematical symbols and, in some cases, pre-defined functions. front end - Answer: User interface to complex structures such as databases, whereby only required fields and the user interface can be seen. The software in the background appears 'invisible' and can only be accessed by an authorised person. FTP - Answer: File Transfer Protocol allows a copy of data to be sent from one computer to another. It controls the data and sends it in blocks, checking each block as it arrives for errors. generic font family - Answer: A term used to describe a collection of fonts with similar properties, e.g. serif or sans serif. In web programming, using a generic font family allows the web browser to select any font stored on the computer with the specified properties. GIF - Answer: Graphics Interchange Format: a format used to save still or moving images. This is an efficient method of storing images using a smaller file size, particularly where there are large areas of solid colour. It is widely used in webpages. global positioning satellite system - Answer: Used to determine the exact location of a vehicle using a number of satellites positioned around the Earth. Each 22 iGCSE ICT Glossary hyperlink - Answer: Allows a user to navigate between webpages/websites and is often shown as a blue underlined text or as a small pointed finger. identity theft - Answer: A form of fraud that involves somebody pretending to be somebody else in order to steal money or gain other benefits. IF - Answer: A function within Microsoft Excel that looks at a given condition and performs an operation if the condition is met, or a different operation if the condition is not met. image source - Answer: The name (and in some cases URL) of an image file, used so the web browser can find and display the image. inference engine - Answer: Software in an expert system that attempts to derive answers from the knowledge base using a form of reasoning. It is effectively how expert systems appear to use human-like reasoning when accessing information from the knowledge base in an effort to find a conclusion to a given problem. infrared - Answer: The far red end of the light spectrum, between the visible and microwave part of the electromagnetic spectrum. inkjet printer - Answer: A type of printer which uses inkjets to produce low- volume, high-quality printing. 25 iGCSE ICT Glossary input screen - Answer: The part of a computer screen where a user types in the data or uses a touch screen or pointing device to choose an option. INT - Answer: A function within Microsoft Excel that calculates the integer (whole number) part of a number and ignores all digits after the decimal point. integer - Answer: A whole number with no decimal places (e.g. 18, 107). internet - Answer: A wide area network consisting of an international network of computer networks. It enables anyone connected to it to get information from any other computer on the system (if permitted). internet protocol (IP) address - Answer: A numerical identification and logical address that is given to a device using a computer network. It uses the internet protocol to allow communication between devices on the network. internet service provider - Answer: A company that provides users with access to the internet for an agreed monthly rental. interview - Answer: Asking people questions face to face as part of the fact finding stage in systems analysis. intranet - Answer: A computer network based on internet technology that is designed to meet the internal needs for sharing information within a single organisation. 26 iGCSE ICT Glossary IP - Answer: See internet protocol address ISP - Answer: See internet service provider itemised bill - Answer: A bill which includes all the items bought and the price of each item plus any discounts or other offers. joystick - Answer: A device that consists of a stick that is moved about to control a pointer on the screen and has buttons to make selections. JPEG - Answer: A format used to save still images, originally named by the Joint Photographic Expert Group. This is an efficient method of storing images using a smaller file size and is widely used in webpages. junk mail - Answer: Unsolicited mail sent to a user's computer, often referred to as 'spam'. key field - Answer: A unique field in a record which is used to identify it uniquely. keyboard - Answer: A device used to input text, numbers and instructions into a computer by pressing keys. 27 iGCSE ICT Glossary mail merging - Answer: The process of combining a main document (e.g. a word- processed document) with a data source (e.g. a database), for example adding names and addresses automatically to a document so it can be easily set up for multiple mailings. mainframe computer - Answer: A very large, very powerful computer system. malware - Answer: Short for malicious software - any program/software that is harmful to a computer system, e.g. spyware. MAX - Answer: A function within Microsoft Excel that calculates the maximum value in a list of numbers. media access control (MAC) address - Answer: Hardware address that uniquely identifies each device on a network. memory stick/pen drive - Answer: A solid state technology that is used as back-up memories. It connects to the computer via the universal serial bus port. merge codes - Answer: Instructions coded (programmed) into a mail merge document which control the format of the merged document and may produce different results (for example: text or images) depending upon other conditions. MICR - Answer: See magnetic ink character recognition 30 iGCSE ICT Glossary microprocessor - Answer: A single integrated circuit that is the basis of most PCs and is in many household devices. It has essentially the same function as a computer processing unit. MIN - Answer: A function within Microsoft Excel that calculates the minimum value in a list of numbers. model - Answer: A programmed simulation of a situation or process that will allow data to be changed in order to examine the effect that this has on other data. This is often done with a spreadsheet and can be used to predict future trends. modem - Answer: A device that allows computers to connect to a network using the existing telephone cable network. monitoring - Answer: Taking data from the surroundings so that it can be compared with previously stored data on a computer or computer file. mouse - Answer: An example of a pointing device, which controls a pointer on screen, allowing selections to be made by clicking a button. MPEG-3 - Answer: Moving Pictures Experts Group layer 3 is a file format used for storing audio files. It compressed the original audio (sound) file to about 1/12 of the original file size while keeping the original sound quality. 31 iGCSE ICT Glossary MPEG-4 - Answer: Moving Pictures Experts Group layer 4 is a file format (multimedia container) used for storing video files. It is also used to store audio (the soundtrack to the video) and other data like subtitles and still images. MP3 - Answer: MPEG-1 Audio Layer 3 - a method of storing music files in a compressed format. Typically, an MP3 music file is 90 per cent less than a conventional music file used on a CD. multimedia projector - Answer: An output device that receives signals from computers (and other electronic devices), magnifies the image and projects it onto a large screen. navigate - Answer: To move around, e.g. navigating a screen or webpage means to move about the page (often using a pointing device) to select suitable items. netbook computer - Answer: A computer that is similar to a laptop but with smaller dimensions. network - Answer: A series of nodes or workstations interconnected by communication paths. network hub - Answer: A hardware device that can have a number of devices/computers connected to it. 32 iGCSE ICT Glossary optical storage device - Answer: A storage device that uses light (lasers) to read and write data on optically active surfaces. They include CDs, DVDs and DVD- RAMs. ordered list - Answer: A list of objects within a webpage that are in numerical order. orphan - Answer: The first line of the paragraph at the bottom of the page, with the rest of the paragraph appearing on the next page. password - Answer: A sequence of letters and/or numbers used as an additional security to user ID when logging onto a network or single computer. paste - Answer: To take a copy of an object from the clipboard and place it in a new location. PC - Answer: See personal computer PDA - Answer: See personal digital assistant PDF - Answer: Portable Document Format is a method of allowing documents to be read/used on most computers. The pages look just like they would when they are printed but can contain clickable links and buttons, form fields, video, and audio. You can protect a document to stop others editing it. 35 iGCSE ICT Glossary PNG - Answer: Portable Network Graphics is a graphics file format that supports data compression. PNG is the most used lossless image compression format used on the Internet. percentage - Answer: A system used in web authoring to ensure that objects have relative sizes rather than absolute sizes. For example, if a table has the width attribute set to 50 per cent, the table will fill 50 per cent of the screen, irrespective of the screen size or resolution. personal computer - Answer: A general purpose computer which is usually IBM- compatible. personal digital assistant - Answer: A small handheld computer that comes with a touch screen activated by a stylus. personal identification number - Answer: A form of password, often a four-digit code used to gain access to an account (e.g. when internet banking or when purchasing an item using a credit card). pharming - Answer: A scam in which malicious code is installed on a computer hard disk or server. The code has the ability to misdirect users to fraudulent websites without their knowledge. 36 iGCSE ICT Glossary phishing - Answer: A fraudulent operation involving the use of emails. The creator sends out a legitimate-looking email hoping to gather personal information once the recipient opens the email. pica - Answer: An absolute measure of size used in website authoring. 1 pica is the same as 12 points. PIN - Answer: See personal identification number pinching - Answer: Using two fingers together to shrink something on a display screen (e.g. on a personal digital assistant). pixel - Answer: One dot or square on the screen. It is the smallest item that can appear on a screen. The number of pixels displayed on the screen depends upon the screen resolution. placeholder - Answer: A control placed within a mail merge document that is used to hold field codes or to hold merge codes. plotter - Answer: An output device that produces very large and very accurate printed copies on paper, generallyused in CAD software. PNG - Answer: Portable Network Graphics: a format used to store still images. This is an efficient method of storing images and was designed to replace JPG (JPEG). It is widely used in webpages. 37 iGCSE ICT Glossary program (verb) - Answer: To create a set of instructions that will produce a required output from an ICT system program documentation - Answer: The written documents that accompany a program upon implementation. It advises on how the program works, what the instructions mean and how to make future amendments programmable logic controller - Answer: A type of computer or microcomputer that is used for a single purpose. It is able to accept analogue and digital inputs, and a set of logic statements is used to compare the input with a pre-set value. Depending on the result, it activates the output devices. See also proportional- integral-derivative programmer - Answer: Somebody who writes programs. See also computer programmer programming language - Answer: A computer-based language that is used to write code that will use a sequence of instructions to perform a task within the computer project management - Answer: A method of ensuring that a project is completed within the timescale and monetary budget allowed by a business prompt - Answer: Text used to instruct the user what information they are required to enter when a mail merge is run 40 iGCSE ICT Glossary proportional-integral-derivative - Answer: An algorithm that is an integral part of closed loop computer controlled systems. It calculates the difference between the input value and the pre-set value, and then causes the programmable logic controller (PLC) to make proportional changes to the output so that the pre-set value is eventually reached protocol - Answer: A set of rules that governs how communication between two devices will occur proxy server - Answer: A computer that lies between a user and a server in order to intercept requests. pseudo code - Answer: A type of code which resembles computer programming code but is easily readable by a person. They are often used in algorithms as a description of what a computer program is going to do. public key authentication - Answer: A feature of encryption that allows one computer to know that a computer trying to communicate with it is genuine public-key - Answer: A type of encryption key that is given out by a computer to enable other computers to encrypt data to send to it purpose-built software - Answer: Software that is especially created by programmers for a particular situation 41 iGCSE ICT Glossary questionnaire - Answer: A collection of questions written down on a form that enables collection of data. The answers to the questions are normally completed on the form itself QWERTY - Answer: Type of keyboard format where the letters are arranged as QWERTY.... radio button - Answer: A type of graphical user interface element that allows the user to choose only one of a pre-defined set of options. They are usually shown as a dot on the screen next to the option. RAM - Answer: See random access memory random access memory - Answer: An internal chip where data is temporarily stored while running applications. It can be written to as well as read from. range check - Answer: Checks that the data is within a given range RAR - Answer: Is a file format for a container (like a zip file) that can hold other files and folders. It its name from Roshal Archive and was developed by a Russian software engineer Eugene Roshal. read only - Answer: Allows a user to view the document/file but not to make changes to it 42 iGCSE ICT Glossary requirements specification - Answer: An element of the analysis phase of the systems life cycle. It is a list of the features of a system that is required, including general user requirements and specific requirements rich text format - Answer: A file format (.rtf) used for text-based files that saves the formatting within the document, so allowing some formatting to be passed from one applications package to another ring network - Answer: An increasingly rare type of network topology. Each computer is connected to each of its neighbours and data is transmitted around the network robot - Answer: A device often used in industrial applications to act independently, having been programmed to carry out a specific task or tasks ROUND - Answer: Function within Microsoft Excel that rounds a number up to a specified number of decimal places Router - Answer: A device which enables data to be routed between different networks e.g. between a local area network and a wide area network. rules base - Answer: In an expert system, a set of rules that an inference engine uses, together with the data or facts in the knowledge base, to reason through a problem 45 iGCSE ICT Glossary sans serif - Answer: A font style where the ends of characters do not contain small strokes called serifs, e.g. Arial. satellite navigation system - Answer: See global positioning satellite system scam - Answer: An attempt to defraud somebody. scanner - Answer: A device that converts information on paper into an image which can be stored in a computer file. scenario - Answer: A description of a set of circumstances. It is used to set the scene for some examination questions screen display - Answer: Sometimes used interchangeably with screen layout, but usually refers to input as displayed on a computer monitor screen layout - Answer: The layout of output as displayed on a computer monitor screenshot - Answer: An image of the screen taken at a particular moment in time. There are software packages that will obtain screenshot (sometimes called screen grab) evidence for you. The easiest way is to press the <Print Screen> (sometimes labelled <Prt Scr>) button on the keyboard to place what is currently on the screen in the clipboard. This can then be pasted into a document as evidence of your work. 46 iGCSE ICT Glossary SD memory card - Answer: See secure digital memory card search engine - Answer: Software that retrieves documents or files or data from a database or from a computer network (especially from the internet). SECOND - Answer: Function within Microsoft Excel that returns a number between 0 and 59 as the number of seconds shown on a clock from a given time secondary research - Answer: A method of market research that involves the examination of research that either the organisation concerned or another organisation has carried out before. See also primary research section - Answer: The area of a document that has page formatting that applies throughout that section secure digital memory card - Answer: A type of memory card used to record digital audio broadcast (DAB) radio programmes and used in digital cameras, handheld computers and global positioning system (GPS) devices secure shell - Answer: A network protocol that is used for remotely accessing a computer or server using encryption security sensor - Answer: A device used to monitor physical variables such as temperature and pressure. They are used in monitoring and control systems 47 iGCSE ICT Glossary software piracy - Answer: Unauthorised duplication, distribution or use of computer software. solid state backing store - Answer: A type of magnetic storage media that uses microchip technology rather than thin film magnetic surfaces. speech recognition software - Answer: Software that is able to convert input speech to text for use with text-based applications spread spectrum technology - Answer: Can be implemented in several different ways, but the most common type involves frequency hopping: instead of just transmitting on one frequency, a spread spectrum system switches rapidly from one frequency to the next. The choice of the next frequency is random, so it is almost impossible for someone to eavesdrop or jam the signal). It is used on cordless phones and in WiFi networks. spreadsheet - Answer: Software used for performing calculations and for modelling situations using data arranged in a grid consisting of rows and columns spreadsheet model - Answer: A spreadsheet that is used to investigate different outcomes by changing one or more variables within it. spyware - Answer: Software put on a computer with malicious intent that allows people to access that computer and control its functions 50 iGCSE ICT Glossary SSH - Answer: See secure shell star network - Answer: A network topology where each computer or device is connected to a central hub or switch sticky keys - Answer: A feature used in many types of software that allows the user to press combination keys such as <Ctrl> C consecutively rather than simultaneously. It is very helpful for people with poor motor coordination storage medium - Answer: A medium used for storing data, e.g. magnetic disk, tape or optical disk style - Answer: Pre-defined settings relating to the formatting of text, such as font size, typeface, font alignment, etc. that can be applied to text to ensure the consistency of display stylesheet - Answer: A basic structure for a document. In terms of a webpage, it is set of pre-defined styles for some or all page elements which can be embedded into a web page submit button - Answer: A button or icon found in many input forms that when pressed causes the data on the screen to be stored subscript - Answer: Characters that sit below the baseline in a piece of text and usually have a reduced point size, e.g. the number 2 in H2O 51 iGCSE ICT Glossary SUM - Answer: Function within Microsoft Excel that adds up a list of numbers or specified cells SUMIF - Answer: Function within Microsoft Excel that looks at the cells within a given range and adds the total from those cells that meet a given condition supercomputer - Answer: A computer that has hundreds of thousands of dual processors. It is a collection of computers that are connected through a high- speed network superscript - Answer: Characters that sit above the baseline in a piece of text and usually have a reduced point size, e.g. the number 2 in 7 m2 switch - Answer: A device that can have a number of other devices or computers connected to it. It is able to direct network traffic using the MAC address of a data packet syntax - Answer: A set of rules defining how, for example, software must be written so the computer can understand it. It is equivalent to syntax in normal language where rules determine how we write down sentences with commas, etc. systems analysis - Answer: A phase in the systems life cycle. When an existing system is to be replaced by a new system, this phase involves examining the existing system in detail using some or all of interviewing users, giving 52 iGCSE ICT Glossary text wrapping - Answer: To make the text automatically wrap around any object (e.g. a text box or frame) in a document topology - Answer: An arrangement of computers/devices in a network (e.g. bus, star, ring or tree). touch screen - Answer: An input device that allows the user to choose from options on the screen by pressing the option on the screen with a finger touchpad - Answer: Used on laptops as a type of pointing device. trackerball - Answer: A pointing device with a ball on the top which controls the on-screen cursor. Unlike a mouse, the trackerball does not physically move. tracked changes - Answer: An electronic record of all changes made to a document during editing. This shows the changes made and usually includes the editor's name and when the changes were made tracking - Answer: See tracked changes transaction number - Answer: A password that is used once only as a security method in online banking transducer - Answer: An electrical device that converts one form of energy into another (e.g. a microphone converts sound energy into electrical energy). 55 iGCSE ICT Glossary transmission control protocol - Answer: A network protocol for the transmission of data that ensures that data is delivered accurately transponder - Answer: A device used for transmitting television programmes. It is attached to a communications satellite, which receives signals from the uplink satellite dish and transmits them back to earth to receiving satellite dishes tree network - Answer: A combination of two or more star networks connected together. The central hubs of each star network are connected to a central cable as with a bus network - thus a tree network is a bus network of star networks. Trojan horse - Answer: A program similar in effect to a virus except that it does not replicate itself. It appears to be a useful piece of software, but when executed deletes files on the hard disk troubleshooting guide - Answer: Part of user documentation that comes with a new ICT system. It advises users on how to overcome commonly occurring problems tunnelling - Answer: The use of a publicly accessible network to carry encrypted data from source to destination computers 56 iGCSE ICT Glossary turtle graphics - Answer: A popular way of drawing shapes on a computer screen (or by controlling a 'floor turtle' that can move around). There are a set number of commands such as RIGHT x, LEFT x, TURN d, etc. tweening - Answer: The process of generating intermediate frames between two graphic computer images to give the appearance that the first image transforms smoothly into the second image. twisted pair - Answer: Type of network cable used to transmit data between devices on a network. It consists of two conducting wires twisted around each other. This reduces the magnetic interference and hence data loss during transmission type check - Answer: A validation check that makes sure that the data is of a particular data type uniform resource location - Answer: The unique address of any document found on the internet. Typically the address is divided into parts. The first part of the address gives the protocol, commonly HTTP, the second part gives the name of the computer (e.g. www.cie.org.uk). There is sometimes a third part which gives the directory on the computer where the document file name can be found universal serial bus - Answer: Serial bus standard to connect devices to a computer. 57 iGCSE ICT Glossary convention, often identifying sequential version numbers and sometimes authors' initials video conferencing - Answer: Audio and visual communication between people at different geographical sites using the internet or some other wide area network. It makes use of special hardware (such as webcams, microphones and speakers) and special software (such as CODEC or communications software). video-on-demand - Answer: A system that allows viewers to watch video over a network. The film is either constantly being transmitted over the network or downloaded in one go to a set-top box, allowing the viewer to watch it at their convenience virtual private network - Answer: The use of publicly accessible networks to communicate private information. It is not physically private but involves the use of security methods that make it practically impenetrable virus - Answer: A software program that can replicate itself over and over again on a hard disk. It also transfers from one computer to another and may modify or delete files from a hard disk visual verification - Answer: A type of verification where data is entered and the original data is compared visually to the data entered into the system 60 iGCSE ICT Glossary VLOOKUP - Answer: Function within Microsoft Excel that looks up data using data organised in vertical columns VOD - Answer: See video-on-demand voice over IP - Answer: The use of the internet to send voice data in the form of digital data packets using internet protocols. VOIP - Answer: See voice over IP WAN - Answer: See wide area network war driving - Answer: The act of searching for WiFi networks by driving around in a vehicle. It requires some form of antenna, a portable computer/personal digital assistant and special software. Web - Answer: See world wide web Web 2.0 - Answer: Second generation of internet development and design. web authoring package - Answer: Software used for creating web pages web browser - Answer: Software that allows you to display webpages from an intranet or the internet. 61 iGCSE ICT Glossary Webcams - Answer: Miniature video cameras that are connected to computers to transmit video across a network. Their main use is in videoconferencing web-enabled mobile phone - Answer: A mobile phone that allows the user access to the internet. weblog - Answer: See blog Webpage - Answer: A single page of information displayed in a format that can be viewed on a web browser through either the intranet or the internet. Website - Answer: A collection of interrelated webpages that relate to one topic or organisation and usually accessible via the internet. white space - Answer: An area of a document that contains no text or images and just contains the paper, hence the term 'white space' referring to the blank colour of the paper. Documents normally have 'white space' between the margin settings and the edge of the page. wide area network - Answer: A network formed by connecting several local area networks together using routers or modems Widow - Answer: A last line of text of a paragraph that appears at the top of a page, with the rest of the paragraph on the previous page 62