The most important thing to understand is that what desktop environment you use has nothing to do with your choice of distribution.
Most window managers are designed to help provide a desktop environment.
It is designed to give users a traditional desktop environment.
Instead, it is which version of the desktop environment you are using that matters.
It is available for many other operating systems and desktop environments as well.
In practice, software written on major libraries can be run under any desktop environment.
Enlightenment is sometimes used as a replacement for a full desktop environment.
Window decorations are important in developing the look and feel of a desktop environment.
When users log in, they can choose the desktop environment to use.
Users can install and run their own desktop environment if they choose.