A Made IT project
When looking at interfaces the are a lot of misconceptions. Some times people call a connector an interface, while in a real interface is more then that. A complete interface consists of three parts:
The connector is defined by it shape, it's size and the amount of pins it holds and of course the place the pins are mounted in the connector housing. Mostly it is built up of a shell (which contains the pins), the pins, the hood and something to mount it with like screw-locks or latches.
The pin assignment describes which pin is connected to which circuit and thus describes the actual function.
The electrical characteristics describe the voltages, currents and shapes of the signals.