Alternatively referred to as a bus slot or expansion port. An expansion slot is an opening located inside a computer on the motherboard or riser board that allows additional boards to be connected. For example, if you wanted to install a new video card in the computer you'd purchase a video expansion card and install that card into the compatible expansion slot. Below is a listing of some of the expansion slots commonly found in IBM compatible computers as well as other brands of computers and the devices commonly associated with those slots. Clicking on any of the links below give you additional details about each expansion slot.