AQA GCSE Computer Science key terms

A unit of data equal to 1,000 gigabytes or 1,000,000,000,000 bytes, written TB. The prefix tera means $10^{12}$.

A planned check that specifies input data and the result the program should produce.

Input values chosen to check whether a program behaves as intended.

The process of checking an algorithm or program against its requirements by comparing actual results with expected results.

A structured collection of test cases chosen to check a program against its requirements.

How quickly an algorithm completes its task, which can be estimated by counting the steps it performs for a given input.

Dividing processor time into small intervals that can be allocated to different programs.

A table used to record changing variable values and outputs while following an algorithm step by step.

Working through an algorithm one instruction at a time, recording changing values and outputs.

A tiny electronic switch controlled by electricity.

Software that translates program source code so its instructions can be executed by a processor.

The layer of the TCP/IP model that enables communication between two hosts, including agreeing settings such as packet size.

Malware disguised as legitimate software, which tricks a user into installing or running it. It does not self-replicate.

A table showing every possible combination of Boolean inputs and the corresponding output for each combination.

An array of arrays that can represent a table or grid, with each individual value accessed using two indexes.

Authentication requiring two different types of evidence of identity, such as a password and a code from a device the user possesses.

A check that input is of, or can be converted to, the required data type.

Using or accessing a computer system or its resources without permission.

Data whose storage size has not been reduced using a compression method.

A character standard that assigns numerical codes to characters from many writing systems, retaining ASCII's assignments from 0 to 127.

An integer represented without a positive or negative sign; all its bits contribute to a non-negative value.

An unintended change elsewhere in a program caused by running a piece of code, such as a subroutine changing a shared variable.

An SQL command that changes values in existing rows of a table.

The means through which a user interacts with a computer system, such as graphical controls or typed commands.

An identifier used to distinguish a user's account from other accounts.

System software that performs a particular task to maintain, protect, troubleshoot or improve a computer system.

A check that input meets specified rules, such as having the correct data type or being within an allowed range.