Slot One type of socket fitted to a computer's MOTHERBOARD into which expansion cards can be plugged.
pcs have several different types of slots. The slots can also act as input/output ports for attaching external devices (such as digital cameras) via a cable. The slots in the original IBM PC could transfer only 8 bits of information at a time between the motherboard and the card in the slot; these are 8-bit slots. The PC/AT was the first PC to have 16-bit slots, and set the standard still followed by most pcs today (see lSA and bus). The 16-bit slots actually have two separate slots arranged in a line; the slot toward the back of the computer is exactly the same as an 8-bit slot.
In other words, you can plug an 8-bit add-in board into a 16-bit slot (but not the other way around, of course). EISA slots are 32-bit slots which accept standard 8-bit and 16-bit boards, as well as special 32-bit boards. Then there are the 32-bit Micro Channel slots, which take only Micro Channel boards. See also full-length slot.