What are input and output devices?

An input is data that a computer receives. An output is data that a computer sends.

Computers only work with digital information. Any input that a computer receives must be digitised.

Often data has to be converted back to an analogue format when it's output, for example the sound from a computer's speakers.

An input device is something you connect to a computer that sends information into the computer. An output device is something you connect to a computer that has information sent to it.

How does input make an output?

The computer sits between the input and output devices. A computer program processes and digitises the input information. The result is then sent to an output device such as a screen.

Think of a DVD player

You click 'play' on your remote control, an input device. It digitises the input and sends this digital information to the DVD player.

The computer inside the DVD player processes this input information and works out what to do. It will start to read the DVD. The video and audio information from the DVD is then sent to the TV screen and the speakers, the output devices.

Think of a games console

When you are playing a game you are using a controller where you push a button or push the control stick to move a character.

These inputs are digitised and sent to the computer to be processed. The program processes the inputs and gives an output. In this case the character on screen moves as it has been programmed to.

The input device in this picture is the remote control. You press 'play', the DVD player processes the information and a film is output on the TV.
Play Bitesize games
Test your maths and times table skills!