What does a computer use in order to work?

For computers to work they need a number of things to be attached or installed.

A reliable electricity supply is needed to enable the computer to work.

A screen to show you what the computer is doing also helps.

A keyboard and a mouse is used by humans to tell the computer what humans want the computer to work on, what the computer is to do, and were is the results to be sent when the work is completed.