[win32] Concept of a window

source: https://docs.microsoft.com/en-us/windows/win32/learnwin32/what-is-a-window- #

In Windows, a “window” is used to represent actual windows, but also widgets. Buttons are also windows.

• Windows can have parent-child relationships between each other. Widgets are children of the windows they reside in.
• Windows can be owned by other windows; in this case they are always displayed above their owner.

Windows have a client area which is rectangle the application can draw to. This is smaller than the whole area the window is rendered in, since the window typically has a title bar and borders. The whole area is called non-client area.

Windows are created via calls to CreateWindow or CreateWindowEx which return a Window handle (HWND) .