It consists of some sort of Taskbar, some sort of Launcher/Startbutton and some application windows.
KDE, GNOME2, XFCE, Windows 95 up to Windows 7 all use this. OSX to some degree. It is all the same.
Am i asking to much if i belive every (non-technical) user should be able to wrap their head around this and get comfortable with this within a few weeks?