Hello, fin_81, you wrote: _> Scenarios of usage of that? The list and an array in one code? The list and dynamic array. _> to me here the scenario , as for me it terms. The HARDWARE the scenarios did not result, and that you there imagined yourself, nobody knows. ArrayList (dynamic array) and LinkedList (list) in a toad, for example, implement the same interface List. And it strongly does not confuse anybody. _> the in itself pattern is an attempt from useless/bad/divine object to make something useful. Well, it is finite: * make a software library easier to use, understand and test, since the facade has convenient methods for common tasks; * make the library more readable, for the same reason; * reduce dependencies of outside code on the inner workings of a library, since most code uses the facade, thus allowing more flexibility in developing the system Where here about useless/bad/divine? _> That is facade presence is a sign of the bad code. For the given specific case, most likely, the adapter turns to a facade. The sign of the bad code is patterns everywhere where only it is possible. And creation simple API (facade) over difficult is a standard reception for the serious libraries, allowing without code duplication to give both idle time API for basic tasks, and expanded for the advanced. Generally, I do not see any sense to divide terms "facade" and "adapter". It only special cases .