Expansion card

An expansion card is a printed circuit board that can be inserted into the expansion slot of a computer motherboard. One edge of the expansion card holds the contacts that fit exactly into the slot. The establish the electrical contact between the electronics (mostly integrated circuits) on the card and on the motherboard.

The earliest type of PC expansion card was built to the industry-standard architecture (ISA) specification and had a metal bracket at one end. This bracket was fastened to the PC case with a screw. Connectors mounted on the bracket allowed the connection external devices to the card. ISA cards are now obsolete and have been replaced by PCI cards.

A PC graphics card (video card, VGA card) is a type of expansion card. It usually sits in an AGP slot on the motherboard (there are cards for other slot types, however), and has a VGA connector to the outside. The monitor cable is attached to this connector.

Slot types include PCI, ISA, AGP, VLB and others (see also PC motherboard).