OCR GCSE Computer Science key terms

System software that manages a computer’s hardware and resources and provides an environment in which applications can run.

A symbol or keyword that performs an operation on one or more values.

A storage medium read using a laser, such as a CD, DVD or Blu-ray disc.

Storage that uses a laser to read data from an optical disc, such as a CD, DVD or Blu-ray disc.

A Boolean operator that produces True when at least one condition is true, including when both are true.

A logic gate whose output is 1 when at least one input is 1.

Data sent out by a program, for example text displayed on a monitor or sound played through a speaker.

An error that occurs when a numerical result is too large to fit in the available number of bits.

An error occurring when a calculation produces a result too large to be represented using the number of bits available.

The execution of different instructions or parts of a task at the same time, using multiple processing units.

A named input in a subprogram definition that receives data when the subprogram is called.

A mesh arrangement in which not every pair of devices has a direct connection.

One traversal through the relevant items in a list. In bubble sort, a pass compares successive adjacent pairs.

A secret sequence of characters entered to gain access to an account or system.

A computer in a peer-to-peer network that can both request resources from other computers and provide resources to them.

A network arrangement in which computers share resources directly without a dedicated central server; each peer can request and provide resources.

An authorised, simulated attack on a computer system to identify security weaknesses so they can be corrected.

A hardware device connected to a computer to provide functions such as input or output, for example a keyboard or printer.

Information relating to an identified or identifiable living person, such as their name, address or medical information.

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

A social engineering attack using fraudulent messages that appear to come from a trusted source to trick recipients into revealing information or taking unsafe actions.

Measures that protect devices, storage media and network equipment from unauthorised physical access, theft or damage.

A single picture element in a digital image, with one specific colour.

The value assigned to a digit’s position in a number. In two-digit hexadecimal, the left position represents sixteens and the right position represents ones.

Readable, unencrypted data.

How faithfully a digital sound recording reproduces the original sound when played.

Post Office Protocol: rules for downloading received emails from an email server to a client, normally removing them from the server.