All PCs have a keyboard port
connected directly to the motherboard. There are two types of keyboard connectors.
The oldest is a special DIN-type connector popularly known as the AT-style.This
keyboard connector was introduced by IBM and was a standard connector for
keyboards then.
As technology grew the AT-style keyboard connectors started to disappear
and a new connector called ps/2 mini DIN became the standard. Most PCs that
use the mini-DIN for both the keyboard and mouse clearly mark each mini-DIN
socket as to its correct use.