System unit

Updated: 11/13/2018 by Computer Hope

Alternatively called a box, main unit, and system box, a system unit is a case containing all the main parts of a computer. Below is a picture of a computer with the main components that help make up a computer. The picture shows the system unit, flat-panel display, speakers, keyboard, and mouse. We've also labeled each of the input devices and output devices.

Desktop computer

Is there a difference between a computer, desktop, and system unit?

No. When discussing the case that holds all the main parts of the computer (e.g., CPU (central processing unit), motherboard, hard drive, and RAM (random-access memory)), all these terms are synonymous.

What are the parts of a system unit?

As the computer has developed into what it is today, many parts make a system unit. See our computer definition for a complete list of all the computer components.

Chassis, Desktop, Enclosure, Hardware terms