.gnome vs .gnome2

Is  there a  document that  describes what  the .gnome  directory does
vs. the  .gnome2 directory? I would  also like to know  the meaning of
the following files/directories:

.gconfd
.gconf
.recently-used
.gnome-desktop
.metacity
.nautilus
.gnome2_private
.gtkrc-1.2-gnome2

I would  prefer functional descriptions ("stores  background colour of
desktop") vs.  jargon descriptions ("stores Nautilus  preferences" - I
have no idea what Nautilus is).

-chris