Computer Science

Pixel: the smallest possible dot on a computer screen which can have its colour set independently; images are made up of pixels

Bitmap: A set of bits that represents a graphic image, with each bit or group of bits corresponding to a pixel in the image

Resolution: the number of pixels per square inch on the computer screen. The higher the resolution, the better the picture

Colour depth: the number of bits used to encode the colour of each pixel Sampling: making physical measurements of the amplitude of an electronic representation of the sound wave at set time intervals and then converting the measurements to digital values Analogue: data which can use any value in a continuous range
Files are compressed to reduce transfer speeds and storage space. With lossless compression, the data in origional file is not changed  

Bus: a bundle of wires carrying data from one component to another or a number of tracks on a printed circuit board fulfilling the same function

Hardware: physical components making up the computer and its peripheral devices.

System software: software that manahes the operation of computer,tells it what to do,tells it which programs to run, controls what the users see on screen etc. Printed circuit board: the base that supports wiring andelectronic components that are soldered to it or fit into sockets on the board.  

ALU:The Arithmetic and Logic Unit (ALU) is the part of the CPU where arithmetic (add, subtract etc) and logic (AND, OR, NOT etc) operations are carried out.

Algorithm: is a set of instructions/steps that are followed to solve a problem.

Integer: Whole number

Boolean: true or false

Float: Can be a whole number or decimal

Array: Named data location for storing multiple values that are all related and of the same data type.

CPU: is responsible for handling/executing all the instructions received from the computer’s software and hardware.

Control Bus: carries signals that control and coordinate all the activities within the computer.

Data Bus:  carries data between the processor, the memory unit and the input/output devices.

Erroneous data: is test data that falls outside of what is acceptable and should be rejected by the system.

Fetch execute cycle: is the basic operation (instruction) cycle of a computer.During the fetch execute cycle, the computer retrieves, decodes and actions a program instruction from its memory.

HTTP: is a protocol used when transmitting files over the World Wide Web.

Volatile: Storage / memory where data is lost when power is removed.

SSD: Solid state drives are non-volatile storage devices capable of holding large amounts of data.

ROM: Read Only Memory (ROM) is a non-volatile memory chip whose contents cannot be altered.

RAM: RAM is a computer’s primary memory.  It is a very fast solid state storage medium that is directly accessible by the CPU.

Register: Registers are high speed storage areas in the CPU.  All data must be stored in a register before it can be processed.

IP address: is a unique number given to every device on the internet.  It signifies the location of the device, allowing devices to communicate with each other.

MAC address: is a unique number given to every device that connects to the internet or a network.  It identifies the actual device.

Magnetic storage: uses different patterns of magnetisation on a magnetisable material to store data.  The data is accessed using read/write heads.

Non Volatile: storage / memory where data is not lost when power is removed.