Window Manager refers to the GUI that controls the appearance of the windows, as their size and placement. Furthermore, Window Managers are in charge of the different buttons often seen on the windows, such as close, minimize, maximize, etc., and scroll bars and menus. According to Wallen, some examples of Window Managers include Enlightenment, Afterstep, FVWM, Fluxbox, and IceWM. In summary, a Window Manager controls what the user sees on the screen.
On the other hand, Desktop Environment enables users to set backgrounds and place icons on the screen. Thus, Desktop Environment is a set of software that allows the standard graphical user interface elements to be available to the user. According to Kourafalos, some of the most common examples of Desktop Environments include Gnome, KDE, and XFCE. The Desktop Environment typically contains complementary apps but not a Window Manager.
Some of the main differences between a Window Manager and a Desktop Environment are that the former is highly configurable and uses less memory and CPU than the latter. Some of the downsides of a Window Manager, however, are that it is not usually as user-friendly, it is not visually appealing, and it does not contain bundles of programs. On the other hand, some of the advantages of a Desktop Environment are that it is usually easier to use and customize. However, it can also be considered slow, especially when used on old hardware. The choice, therefore, depends on the specific requests of the user.