Previous Window

  To set focus in the reverse order of Next Window, choose
  Previous Window from the Workspace menu.

  This can be useful to circulate through all the windows on the
  screen.  It differs from shuffling windows.  Next Window will
  always go to the next window even if it is not obscured and it
  will always make that window active.

  For example, if you have three windows:  a clock, the session
  manager, and a DECterm, which is active.  If you select
  Next Window, then the clock may become active.  If you
  select Next Window again, then the session manager will
  become active.  If you choose Previous Window, then the
  Clock becomes active again.