Computer Science key terms

Storage that records binary data using magnetised regions on a surface, such as a hard disk platter or magnetic tape.

The ease with which a program can be understood, corrected and modified after it has been written.

Software deliberately created to harm a computer system, disrupt its operation or gain unauthorised access to information.

A recognisable pattern or characteristic used to identify known malicious software.

A unit of data equal to 1,000 kilobytes using the decimal convention.

A value identifying a particular location in memory, rather than the contents stored there.

The CPU register that holds the address of the memory location being accessed to read or write data or instructions.

A register that temporarily holds data or instructions being transferred to or from memory.

The allocation and tracking of main memory for programs and data, including managing their transfer into memory when needed.

A sorting algorithm that repeatedly divides a list into smaller lists, then merges those lists back together in order.

A network arrangement in which devices have connections to multiple other devices, providing alternative paths for data.

Additional data about a file. For an image, this can include its width and height in pixels, colour depth and creation date.

A section of a program that performs a particular task and can be developed and tested separately.

An operation that returns the remainder after division; written as MOD in OCR pseudocode.

The leftmost bit in a binary representation, occupying the position with the greatest place value. In an unsigned 8-bit number, its place value is 128.

The running of multiple programs apparently at the same time, supported by the operating system’s management of memory and processor time.

An agreed pattern for naming variables, constants and subprograms consistently.

Placing one programming construct inside another, such as a selection inside a loop or a loop inside another loop.

A situation in which demand for a network's capacity is high enough to cause delays and slower data transfers.

Hardware that connects a device to a network, using a wired or wireless connection.

Hardware in a device that enables it to connect to a network and send and receive data, using a wired or wireless connection.

The arrangement of devices and connections in a network.

A group of 4 bits, equal to half a byte.

A device connected to a network, such as a computer, printer or switch.

Memory or storage that retains its contents when its power supply is switched off.

Data which should be accepted by a program without causing errors.

A Boolean operator that reverses a Boolean value: True becomes False and False becomes True.

A logic gate that reverses its single input: 0 becomes 1 and 1 becomes 0.

Ready-made software supplied for general use rather than developed specifically for one customer's requirements.

A linear collection of elements in which one index identifies an element.