What is "parenting" and how does it work?

[David <wizzardx gmail com>]

Hi. I'm a brand new Dia user (graphviz isn't working out for me on one
of my charts).

I'm using Dia version 0.96.1 (on Debian Sid)

I've figured out most of what I need to know, but there is still one
(main) thing that puzzles me. What is "Parenting"? I see it under the
Object menu, but can't find a way to activate it. I can't find info on
it anywhere on the docs or website either, except in a few obscure
changelogs which talk about it being some kind of new feature.

Could someone explain this feature, or point me to docs where I can read more?

Thanks,

David.