Object-oriented programming in Java.
As it has been discussed, objects show the interaction which takes place with outer world via certain methods being exposed by them. Interface of object is formed by the methods, with outer world; buttons which are present at television set are the interface b/w electrical wiring and you. Power button is pressed to turn it off or on.
Its common form shows that interface is related methodís group along with empty bodies. Behavior of cycle which is being specifief to be an interface