It is a D-sub connector with E shell and is often miscalled as DB-9. They were developed as the main port for serial connections using RS-232 protocol but most of the applications did not require all the pins. The pin out diagram of a PS2 female connector is shown below. PS2 connectors are color coded as purple for keyboard and green for mouse.
It was introduced with IBMs Personal Systems2 series of computers and hence the name PS2 connector. Picture Doctor 3 0 Serial Port Series Of Computers Picture Doctor 3 0 Serial Port Series Of Computers.
