Interface general

In general there are several different interfaces, almost everything can be classed as an interface. an example of this is something simple like a washing machine. You simply set up the commands and it reacts by doing whatever you say. Also I will explain how it is. By flicking on a light switch you input the flick, the output is the light coming on. That is how they work. Same with a lamp, you flick, push, touch or just simply plug in and the light comes on.