Desktops Computers were so called because a PC Desktop Computer of this class is small enough to sit on a common desktop. This is in contrast to Laptop Notebooks which are small and light enough to sit on one's lap while in use.

The main components Desktops Computers are: the case which encloses the inner parts such as hard disk, processor and ram, sits on a desktop. The monitor then sits on top of the desktop computer case, and an external mouse and keyboard is attached to it.