AQA - Computer Science Terms

All the terms of computer science to actually remember.

Hardware

The parts of a computer which you can physically touch or see

Software

The parts of the computer which run on the hardware and perform tasks.

Arithmetic and Logic Unit (ALU)

Carries out calculations and logical decisions like addition, subtraction, division, multiplication, greater than, less than, etc.

Control Unit (CU)

Decodes instructions and sends out signal to control how the data moves around the CPU and Memory to execute these instructions.

Universal Series Bus (USB)

Transfers data and power supply between external devices and computers.

Data Bus

Carries data between the CPU and the memory

Control Bus

Carries control signals around the CPU and memory

Address Bus

Carries memory addresses for locations to be read from or written to between the CPU and memory.

Register

Memory locations within the CPU that hold data and instructions temporarily for processing. This allows them to be accessed quickly.

Accumulator (ACC)

Register that stores the results of any calculations made by the Arithmetic and Logic Unit.

Current instructions register (CIR)

Register that stores the most recently fetched instructions while it is waiting to be decoded and executed.

Memory address register (MAR)

Register that stores the locations in memory to be used by the MDR, that is where to locate the data is needs to fetch or where to send data it needs to store.

Memory data register (MDR)

Register that is used to store any data fetched from memory or any data that is to be transferred or stored in memory.

Program Counter (PC)

Stores the address of the next instruction.