Examples of Linux desktops are Gnome, Unity, KDE, and XFCE. This article explains the difference.
By Danny Stieben at MakeUseOf.com…
If you’ve been introduced to the world of Linux, it probably didn’t take too long to notice that it doesn’t have a single “face”. Linux can sport all kinds of desktop environments, or none at all. That alone is one of the great benefits of Linux among many more.
via What’s The Difference Between Linux Desktop Environments? [Technology Explained].