Backplane

A backplane comprises a printed circuit board that connects several connectors in parallel to each other, so that each pin[?] of each connector is linked to the same relative pin of all the other connectors. It is used as a backbone to connect several printed circuit board cards together to make up a complete computer system. One popular early computer system that used this approach was called the S-100 bus because the connectors used had one hundred pins. Some computers like the Apple II and the IBM PC integrated an internal backplane for expansion cards.