We see to create GUI of an application, we need to follow below clue

     window->conformant->naviframe->box->label(button, …)

Every other things in the clue except conformant seems has concreate meaning. For example, window corresponds to the whole screen of the phone, box corresponds to an area where can put in some sub elements, such as label, button and so on, the naviframe is a container which can put a series of boxes in.

But what is conformant? it seems a concept more abstractively. We just know conformant goes inside the window first and everything created from now on is inside it. But what is the usage for it? Why we need such an abstraction?

Anyone who can help to explain it?