Does Plone support distinct sets of users in subgroups?

[wheel]

I'm not sure if this is the right venue for Plone questions, if not, 
could someone ref me to a better one? The discussion groups on the plone 
site are mailing lists and I'd rather not subscribe quite yet.

Does plone support distinct sets of users? That is, on a public website 
running plone, can it be configured such that when a user logs in they 
are allowed access to a subgroup's main page, get the subgroup's 
newsletter as well as the main site's newsletter etc? So, a membership 
account on the main site would allow entrance into groups they belonged 
to. Everyone, that is each subgroup, would have access to the same set 
of features that the main site offers,  but would see their own distinct 
version of each, managed by it's own admins. Say each subgroup had a 
photo gallery and forum, each subgroups would be separate. Ideally a 
membership in subgroup A would not preclude membership in subgroup B.