1) A printed-circuit board that plugs into one of the computer’s expansion slots, allowing the computer to use one or more peripheral devices such as disk drives. 2) A printed-circuit board or card connected to the bus in parallel with other cards.

1) A printed-circuit board that plugs into one of the computer’s expansion slots, allowing the computer to use one or more peripheral devices such as disk drives. 2) A printed-circuit board or card connected to the bus in parallel with other cards.