card (or expansion card , board , or adapter)

A card (or expansion card , board , or adapter ) is circuitry designed to provide expanded capability to a computer. It is provided on the surface of a standard-size rigid material (fiberboard or something similar) and then plugged into one of the computer's expansion slot s in its motherboard (or backplane ). Cards may come in one of two sizes designed to match standard slot dimensions. A card can actually contain the capability within its circuitry (as a video card does) or it can control (through an extended connection) a device (such as a hard disk drive).