Window Manager

A window manager is a piece of system software for X that controls the placement of windows within a Graphical User Interface (GUI). It controls several features of the GUI, such as the borders, title bar, size, and the ability to resize the windows. It can be provided as a part of the desktop environment, such as Kwin in KDE Plasma, with features such as icons and toolbars and the ability to provide a more consistent User Interface (UI). Alternatively, it can be standalone (such as i3) to give the user the ability to create a more lightweight and customisable environment. There are 3 main types of window managers: #Stacking/Floating provide the traditional desktop experience such as Xfwm in XFCE, #Tiling where the apps 'tile' so none overlap often with minimal or no reliance on the mouse such as AwesomeWM and #Dynamic which can switch between stacking and tiling window layouts such as Dwm. 

Types of Window Manager

Stacking/Floating Window Managers

Floating window managers are recognizable to most computer users. They feature windows that are "floating," being able to move them freely and overlap each other. Some popular examples are listed below.

• Enlightenment
• KWin
• Muffin
• Mutter
• Xfwm

Tiling Window Managers

Tiling window managers automatically align and snap windows to take up as much screen-space as possible, unless configured otherwise. Some popular examples include:

• awesome
• bspwm
• dwm
• i3
• qtile
• xmonad