Re: what are the respective tasks of windows manager, desktop, and the gui app

Thanks for your answer.
I think what I am confused are questions below:
1. Does the desktop depend on the window manager heavily ?
Without a desktop but just a window manager and the X server,
can we start up some GUI program, such as the terminal emulator,
and with the help of the window manager, will the emulator have the
window boarder and be dragged to anyware using the mouse ?
2. when we click a pull down menu, is it the gui app itself telling
xserver to
draw menu , or the gui app just communicates with the window
manager,
then the window manager takes care the rest of all? Such as sending
requests
to draw the menu in the style it likes.
3. when the menu disappears after a click, is it the window manager
that restoring
the original gui app's clinet area ? the gui app does not know at all
that part of its
client area have been overlayed and restored. ?

Well, I am very puzzled about issues of this kind.

Thanks.
Jason
.