The central processing unit (CPU) is the portion of a computer system that carries out the instructions of a computer program, and is the primary element carrying out the computer's functions.

In computing, a keyboard is a typewriter keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. With the decline of punch cards and paper tape, interaction via teletype-style keyboards became the main input device for computers.

A computer mouse with the most common standard features: two buttons and a scroll wheel, which can also act as a third button.

 

A monitor or display (sometimes called a visual display unit) is an electronic visual display for computers.

Cockpit voice recorder (on display in the Deutsches Museum). This is a magnetic tape unit built to an old standard TSO C84 as shown on the nameplate. The text on the side in French "flight recorder do not open"