Term of the Moment

blockchain economy

Look Up Another Term

Redirected from: interface card

Definition: expansion card

A printed circuit board that plugs into a slot on the motherboard and enables a computer to control a peripheral device. Also called an "interface card," "adapter" or "controller," all the printed circuit boards that plug into a computer's bus are technically expansion cards, because they "expand" the computer's capability. PCI and PCI Express are common expansion cards in use today (see PCI and PCI Express).

Cards Used to Be the Norm
In earlier PCs, controllers for drives, input/output ports, display, network and sound all resided on separate plug-in cards. Subsequently, peripheral control was built into the chipset (see PC chipset); however, users still have options to install their own controllers. For example, in order to enhance video game performance, a faster graphics card is plugged into a PCI Express slot, and the internal display circuit on the motherboard is disabled. See motherboard and expansion port. See also bus extender.

Card Types
Today, PCI Express (PCIe) is the card interface in common use. These are the expansion cards in desktop computers since the IBM PC AT in 1984. For a brief description of each, see PC data buses. See PCI Express.

Cards Galore
Cards come in many shapes and sizes, but they all conform to the specific pin format on the motherboard sockets. These are graphics cards and Ethernet adapters with some sound boards thrown in for good measure.