The RadWindow has three states:
Normal - this is the default state of the window and it appears as defined in the code.
Minimized - in this state the window is minimized.
Maximized - in this state the window is maximized.
The state of the RadWindow can change depending on the user actions, but it can also be controlled from the code-behind. This is done by setting the WindowState property which is of type WindowState enumeration.
Every time when the RadWindow changes its state, the WindowStateChanged event is raised. More about the RadWindow events can be found here.