Computer Architecture

Lesson 1

An introduction to Hardware:
Input and Output Devices

What is a Computer?

• A computer is an information processing machine.

• It takes input (what you enter), processes it and makes output

Every computer does things in the same way. There is a CPU (processor) that makes all the decisions, taking input from the user, input devices, backing storage and what is in the current memory, and creating user-understandable output.

Parts of a Computer System

An input device is anything that connects to a computer - directly or remotely - and sends data into its CPU and Memory.

Input Devices

An output device is anything that connects to a computer and gives processed data and information to the user.

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​Output Devices

So What Is Hardware?

Basically - any computing component you can touch.

Hardware is a very broad definition, and includes data cables etc. It should be noted that Input/Output devices are all Hardware, but that all hardware is not necessarily Input/Output devices.

The part of a computer that all the internal components plugs into. It includes the sockets to plug external devices into.

Motherboard

Central Processing Unit - the heart of any computer. This is the part that makes all the decisions.

CPU

The part of the computer that holds all the data for all the currently running programs. When the computer is turned off everything goes from internal memory.

Main Memory (RAM)

​Graphics Processing Unit - can be a separate plug-in card or part of the CPU. This runs the graphics for the computer.

GPU