Variable
A named area of storage that holds a value that may change during or between programs
Constant
A named area of storage that holds a value that does not change
Debug
To check through a program for errors and correct them
Hardware
The pieces of physical equipment that make up a computer system
Software
The instructions that make a computer function in a required way
Event-driven programming
Computer programs that are designed to react to external events such as prompts from the user
Syntax error
A mistake in a Computer program that breaks the rules of the computer language. This prevents the program from being converted to machine code.
Data processing
Transforming data into information by organising it and making it more useful
Data
A general term for facts or figures. Before they are input, items of data have not been processed or organised.
Information
Data that has been processed or organised by the computer to make it more useful to the human user. It is the output from a computer system.
Digital
This kind of data is stored inside the computer in the computer in the form of on/off electronic signals
ROM (Read Only Memory)
The permanent read-only memory which holds the computer's start up software or BIOS. It cannot be changed.
RAM (Random Access Memory)
The active electronic memory which stores the software and data currently in use by the computer. It can be accessed and changed.
Volatile memory
Memory that loses its content when electrical power is turned off
ASCII (American Standard Code for Information Interchange)
A code used to convert characters into numbers for computer storage and transmission
Pixel
Short for "picture element", the smallest changeable part of a picture
Binary
Numbers in base 2. They are formed from the digits 1 and 0 only.
Hexadecimal
Numbers in base 16
Data type
Data stored using a particular storage method. Different storage methods allow different types of data to be stored.
Concatenating
To add two or more strings together to create a longer string using the & symbol
String (data type)
Any group of text characters
Char (data type)
A single text character
Boolean (data type)
True or False / Yes or No
Integer (data type)
A whole number with no decimals
Decimal (data type)
A number that can include decimals
Date (data type)
Any date, the kind on a calendar
BIOS (Basic Input/Output System)
PC software that starts up the system hardware and loads the operating system
Arithmetic Operator
A symbol used to create a mathematical formula e.g. + - / x
Run-time error
A mistake in a computer program that does not prevent it being converted to machine code, but prevents the computer from running the machine code.
Condition
A logical test that can have the result true or false
Relational operator
A symbol used to compare two values. The comparison can either be true or false. < > = <> >= <=
Logic error
A mistake in the program that does not prevent it from running, but means it does not produce the expected results
Verification
Double check on data input to ensure there are no errors. Two forms: enter data twice; visually check data against its source.
Validation
Check input for errors using rules e.g. rules about data type or size of a number
Loop
A step in an algorithm that may be repeated one or more times
Iteration
One repetition of of a loop
Algorithm
A series of steps that will resolve a problem, given in sequence with a clear start and end
Array
A group of variables of the same data type called elements. Elements have the same variable name, distinguished by an item number.
Counter-controlled loop
A loop that repeats a set number of times, then stops