Computer Science Theory

What is a motherboard?

The main circuit board that connects computer components and allows them to communicate.

What is RAM?

Volatile memory that temporarily stores programs and data currently in use.

What does the CPU do?

Fetches, decodes and executes instructions, processing data.

What is CPU clock speed measured in?

Gigahertz (GHz).

What does a PSU (Power Supply Unit) do?

Converts AC electricity from the mains into DC electricity to power the computer's components.

What is the purpose of a cooling fan?

Removes heat from computer components to prevent overheating.

What is an HDD (Hard Disk Drive)?

A secondary storage device that uses magnetic spinning platters to store data.

What is an SSD (Solid State Drive)?

A secondary storage device that uses flash memory and has no moving parts.

What is one difference between an HDD and an SSD?

An HDD uses magnetic spinning platters, whereas an SSD uses flash memory and has no moving parts.

Why is an SSD generally faster than an HDD?

An SSD has no moving parts, allowing data to be accessed faster.

Define Hardware

The physical components that make up your computer

Define Software

The programs that run on your computer

Define peripherals

External hardware devices connected to a computer E.G. Mouse, Keyboard

What is the Von Neumann architecture?

A computer architecture where instructions and data are stored in memory and processed by the CPU.

What is the Fetch–Decode–Execute cycle?

The repeated process the CPU uses to carry out instructions.

What happens during the Fetch stage?

The CPU gets the next instruction from memory.

What happens during the Decode stage?

The CPU interprets the instruction to work out what needs to be done.

What happens during the Execute stage?

The CPU carries out the instruction.

What happens after Execute?

The CPU returns to the Fetch stage to get the next instruction.

What is the order of the Fetch–Decode–Execute cycle?

Fetch → Decode → Execute

Why is the cycle repeated?

A program contains many instructions that the CPU must process one after another.

Define the Control Unit (CU)

Directs and coordinates data flow and instructions inside the CPU.

Define Arithmetic Logic Unit (ALU)

Performs all arithmetic and logic calculations during the execute stage.

`What is the function of the Memory Address Register (MAR)

Temporarily holds the memory address of data/instructions to be read from or written to RAM.

What does the Memory Data Register (MDR) do

Temporarily stores data/instructions fetched from RAM or waiting to be written to main memory.

What does Program Counter (PC) carry out

Stores the memory address of the next instruction to be fetched and executed.

What is the function of the Accumulator (ACC)

Temporarily stores the results of calculations performed by the ALU.

Define Cache Memory

Small, high-speed, volatile RAM close to the CPU that stores recently used data and instructions.

What is the Bus

A collection of parallel wires that transmits data, instructions, and signals between the CPU, RAM, and hardware components.