Such cards are video cards, sound cards, modems, image capture cards, etc.
Cards are one of the most simple topics in computer hardware.
You buy the kind of card you want, stick it in the slot, and load the new drivers. There are a few things to worry about, but they will be discussed on the following page. Slot Types Nerds call a slot a bus . This is the most widely used bus, because it is the original. If you open up an old 286, you'll see a couple of these.