Just curious what the major difference would be from Gnome/KDE/Xfce and various window managers (Fluxbox, IceWM). Could I run Linux with just IceWM/Fluxbox, or is it installed with/over Gnome, etc? I am pretty familiar with Gnome, but I am curious to try out a really lightweight windows and the Terminal together. Not even sure if this is possible.
If it is, what Distro supports it without major hacking?
Desktop environments (DE's) like Gnome/KDE come with a terminal, file manager, text editor, and other apps whereas window managers (WM's) just handle the windows that open under the Xserver. You need to add the extra applications you want to run such as those mentioned above.
Yes, you can run Linux with nothing more than IceWM, Fluxbox, or other WM's by themselves, with no need for a big DE.
check this thread. its a good read.