Window manager (WM) is a system program that controls the position and decorations of windows in systems that use graphical interface. Common operations provided by window managers are: opening, closing, minizing, maximizing, moving, resizing, tracing of windows and decorations managing.
Many window managers are also equipped with utilities and practical software, such as docker, task bar, program launcher, desktop icons and wallpapers.
Window managers can be categorized into three types according to their ways of painting and refreshing windows.
It creates and draws all windows seperately, then composing them to a integral look in 2D or 3D environment. It is also the most advanced type.
Typical mixed WMs are:
It organizes the screen in a way that windows are not overlapped. In contrast to traditional organizing method, it tries to simulate the style of desk where things (windows) are placed according to their coordinates.
Typical tiled WMs are:
The window manager that allows overlapping and cascading of windows.
Typical cascade WMs are: