The types of window manager
The key job of a window manager is to give borders to all open windows, and enable users to move them around the screen. The window managers are classified into different categories depending on how they handle windows.
Stacking window and allow windows to overlap one another; you only interact with the topmost window at any given time. The trouble with the stacking implementation is that it requires windows to be redrawn when they’re brought in focus. A common problem of this approach can be seen when a window becomes unresponsive, and retains the contents of some other window that occupied the same space on the screen, resulting in garbled content on the screen.
