The Apple device contains the socket, and the cable or docking station has the plug. In 2012, the original 30-pin analog+digital interface was replaced with the 8-pin all-digital Lightning connector.

For example, the analog VGA monitor interface uses a D-sub 15-pin plug and socket. Also called "DB connectors" and "D-subs," they come in 9, 15, 25, 37 and 50 pin varieties.