Differences between groups at mozilla.org and netscape.com?

[velociraptor]

There are identically named *mozilla* newsgroups at the servers news.mozilla.org and secnews.netscape.com - what is the (intended) difference between them? Posted articles seem to be quite different e.g. in the group netscape.public.mozilla.mail-news but the amount of articles is *much* less in the netscape.com groups.
OTOH the group n.m.developers.general seems to only exist at the netscape server. I must admit that I am puzzled ...