the window tree, window-combination-limit

[Mike Kupfer <m.kupfer@acm.org>]

The discussion for bug 25055 mentioned the variable
window-combination-resize.  Since I frequently use balance-windows after
splitting or deleting a window, window-combination-resize looked worth
investigating.  Its docstring (in 25.1.90) says

  This variable takes no effect if the variable ‘window-combination-limit’ is
  non-nil.

so I also looked at window-combination-limit.  I have a couple questions
as a result.

The default value for window-combination-limit is 'window-size', which
is documented as

  ‘window-size’ means that splitting a window for displaying a buffer
      makes a new parent window provided ‘display-buffer’ is supposed to
      explicitly set the window’s size due to the presence of a
      ‘window-height’ or ‘window-width’ entry in the alist used by
      ‘display-buffer’.  Otherwise, this value is handled like nil.

After several attempts I can parse the first sentence, but I'm having
trouble understanding its significance.

More generally, as a user, should I care about the window tree and
parent windows?  A web search on

  emacs parent window

gives me several hits in the Emacs Lisp Reference Manual, but I don't
see anything about the window tree in the Emacs Manual.  Can someone
explain the different values for window-combination-limit in terms of
what I would see as a user?

Thanks for any illumination.

mike

"I understand just a little
No comprende--it's a riddle" --Wall of Voodoo, "Mexican Radio"