The Desktop Environment is the graphical user interface that a person uses to interact with a computer. It sits above the Window Manger level. If you imagine a computer system as a series of layers it would look something like this:

• Hardware < Operating System < Window System < Window Manager < Desktop Environment

In most Puppies the default is: (JWM or Openbox act as the desktop environment)

• Hardware < Linux < X Windows < JWM or OpenBox

EDE
GNOME
KDE
LXDE
Mate
Trinity
Xfce- Fully featured lightweight desktop environment.

EDE forum page
GNOME forum page
KDE forum page
LXDE forum page
Trinity 3.5.15 thread
XFCE forum page

Window Managers
Window Managers with Special Effects