D-sub cable assemblies contain two or more parallel rows of pins or sockets usually surrounded by a D-shaped metal shield that provides mechanical support and some screening against electromagnetic interference. The D shape guarantees correct orientation. The part containing pin contacts is called the male connector or plug, while that containing socket contacts is called the female connector or socket. The socket's shield fits tightly inside the plug's shield. The shields are connected to the overall screens of the cable assembly (when screened cables are used), creating an electrically continuous screen covering the whole cable assembly and connector system used for computers, custom application, etc.