BGCSE Computer Studies 0597 key terms

The main component that fetches, decodes and executes program instructions, performing arithmetic and logical operations and controlling the other parts of the computer system.

The part of the processor that carries out arithmetic operations such as addition and subtraction, and logical comparisons such as AND, OR and greater-than tests.

The processor section that directs operations by decoding instructions and sending control signals that coordinate the movement of data between memory, the ALU and input/output devices.

Fast internal storage that holds the instructions and data currently in use; it is volatile, meaning its contents are lost when power is switched off.

A small, very fast store close to the processor that keeps frequently used instructions and data so that the slower main memory does not have to be accessed so often.

Non-volatile backing storage such as hard disks, solid-state drives and optical discs, used to keep programs and files permanently when the computer is switched off.

Hardware that converts data from the outside world into a form the computer can process, for example a keyboard, mouse, scanner, microphone or barcode reader.

Hardware that presents processed results to the user in a readable form, such as a monitor, printer, speaker or projector.

System software that manages hardware, memory, files and running programs, and provides a user interface so that people and applications can use the computer.

A small piece of system software that performs housekeeping tasks such as virus scanning, disk defragmentation, file compression or backup.

Software that tells the operating system how to communicate with a particular piece of hardware, translating general commands into signals that the device understands.

The part of a program through which a person interacts with the computer, such as a graphical interface with windows and icons or a typed command line.

Programs written to help users carry out particular tasks, such as word processors, spreadsheets, browsers and games, rather than to manage the computer itself.

Application software for creating and editing text documents, offering features such as formatting, spell checking, tables, headers and mail merge.

Application software that arranges numbers in rows and columns of cells, allowing formulas and functions to recalculate results automatically when values change.

An expression entered into a spreadsheet cell that calculates a value from other cells, beginning with an equals sign and using cell references and operators.

The smallest unit of data in a computer, a binary digit that has only one of two values, 0 or 1.

A group of eight bits treated as a single unit; it is commonly used to store one character and is the basic unit for measuring file size.

A base-two number system that uses only the digits 0 and 1, which matches the two states a computer circuit can easily represent.

The everyday base-ten number system that uses the digits 0 to 9, with each place value ten times the one to its right.

A base-sixteen number system using digits 0 to 9 and letters A to F; it is used as a short, readable way to write long binary values.

An agreed list that gives every letter, digit and symbol a unique numeric code, such as ASCII or Unicode, so that text can be stored and exchanged.

A unique number that identifies a particular storage location in memory, allowing the processor to find the data or instruction it needs.

A network that connects computers within a small area such as a room or a single building, usually owned and managed by one organisation.

A network that links computers over a large geographical area, often using communication links owned by telecommunications companies rather than the organisation itself.

A device that joins networks together and forwards data packets towards their destination by choosing an appropriate path.

A unique numeric label given to a device on a network so that data can be sent to it and replies can find their way back.

The internet service that translates a human-friendly name such as a website address into the numeric address computers use to locate the server.

The full address of a resource on the internet, showing the protocol, the server name and the path to the particular page or file.

A method of sending data across a network by splitting it into small packets that travel independently and are reassembled in order at the destination.

Software that creates, stores, queries and controls access to a database, handling tasks such as validation, security and concurrent use by many people.

A field whose value is unique for every record in a table, used to identify each record reliably and to link tables together.

A single item of data about an entity in a database table, such as a surname or date of birth, stored as one column for every record.

A complete set of related fields describing one entity in a database table, for example all the stored details about one student.

A request for information from a database, written in a query language or built with a tool, that selects records meeting stated conditions.

A finite, ordered set of unambiguous steps that solves a problem or completes a task, often written as pseudocode or a flowchart before coding.

A diagram that represents the steps of an algorithm using standard symbols such as ovals for start and end, rectangles for processes and diamonds for decisions.

A structured, English-like way of writing program logic that is not tied to any particular programming language and can be easily translated into code.

A programming construct that repeats a set of statements, either a fixed number of times or while a condition remains true.

A programming construct that chooses between alternative paths of action by testing a condition, as in an if-then-else statement.

A data type with only two possible values, true or false, used for conditions and for storing simple yes-or-no facts.

Automatic checking by a program or database that data entered is reasonable, for example a range check or a presence check, before it is accepted.

Checking that data has been copied or transferred accurately and matches its source, for example by double entry or by visual comparison.

The staged process of building an information system, typically covering investigation, analysis, design, implementation, testing, installation, documentation and review.

An early investigation that judges whether a proposed system is technically possible, economically worthwhile and acceptable within the time available.

The documented description of what the people who will use a new system need it to do, gathered during analysis and used to judge the finished system.

A working, simplified version of a system built early so that users can try it and give feedback before the final version is developed.

Any software written to cause harm or gain unauthorised access, including viruses, worms, trojans, spyware and ransomware.

A malicious program that attaches itself to a legitimate file and spreads when that file is run, often damaging data or disrupting normal operation.

A utility that scans files and memory for known malicious code, removes or quarantines what it finds, and should be kept updated to recognise new threats.

Hardware or software that filters network traffic entering or leaving a computer or network, blocking connections that do not match allowed rules.

Scrambling data using a key so that it cannot be understood by anyone who intercepts it, with only the authorised holder able to decode it.

A trick in which a criminal sends a fake message pretending to be trustworthy in order to persuade someone to reveal passwords or bank details.

A copy of data or programs kept separately so that information can be restored if the original is lost through failure, theft or damage.

A device that measures a physical quantity such as temperature, light or pressure and sends the reading to a computer system as data.

A programmable machine that can sense its surroundings and carry out physical actions, often used in manufacturing or in dangerous environments.

Computer systems that perform tasks normally needing human intelligence, such as recognising speech, translating languages or making recommendations from data.

Working from home or another remote location while connected to the workplace by computer and network links, reducing travel but needing reliable communication.

The gap between people who have affordable access to computers, the internet and the skills to use them, and those who do not.