An opening in a
computer where you can insert a
printed circuit board. Slots are often called
expansion slots because they allow you to expand the capabilities of a computer. The
boards you insert in expansion slots are called
expansion boards or
add-on boards.
Do not confuse slots with bays. Bays are sites within the computer where you can install disk drives. Typically, slots are in the back of the computer and bays are in the front.