I read somewere that Unity is a DE, is that true or not?
It depends on definition of desktop environment. But I think Unity is not a DE -- there are no "Unity applications" (Ubuntu mostly uses Gnome applications), window manager is Compiz (not "Unity-specific"), desktop manager is Nautilus (from Gnome) etc.
I think Unity is just of user interfaces for Gnome Desktop Environment.
It's wrong. Unity is a window manager plugin (for Mutter or Compiz) and runs on top of Gnome.
It depends on how you define a Desktop Environment. One definition is "a graphical user interface that runs on top of a computer operating system". By this then I would argue yes - Unity is a different interface and user experience.
The Unity website describes it as "A powerful desktop and netbook environment things brings consistency and elegance to the Ubuntu experience."
Having said this, whilst GNOME is considered a DE then Unity does not completely replace GNOME by any means - the rest of GNOME will be used by Unity, only the very top layer is changed. (In fact Unity could be quite happily used on top of KDE as well.)
- No that's not true UNITY is not a Desktop Environment.
- It's just an interface.
- Desktop Environment is Interface + Program Suite + UI Frame Work + HIG
Have a look at the following links,