what is the difference between a desktop environment and a window manager.
I know that kde and gnome is a DE and Blackbox is a WM is their some difference other than the look?
A desktop environment provides a consistant application framework. KDE is built with the qt toolkit and KDE application are built with qt as well. Plus, KDE applications reuse use moduals and componets, keeping everything tightly integrated. Same thing with Gnome (except with the gtk tool kit). The result is that everything looks and works the same.
Window managers can have taskbars and popup menus (like IceWM), but the do not have the under laying tool kits, widgets and frame works of DE's.
DE's tend to be easier to use and more "pointy-clicky" like Mac and Windows, but at the cost of need more system resources and being more complex.
WM's use less resources and tend to be faster, at the expense of being a bit more minimalistic and having a steeper learning curve.