STARS Interoperability/Mutual Aid Talkgroups

Can anyone advise what the distinctions are between the various kinds of Interoperability/Mutual Aid Talkgroups on STARS (ie, Interop* vs MCall* vs MComm* vs Mutual* vs State 1)?

Do a google search for the December or January? issue of the Capital Hill Monitors Digest? and download it. It has a brief narrative article discussing a few of the less used but STARS common talkgroups.