How do I know if CIM is working in IT Assistant? What is the difference between CIM and SNMP?

I've had a hard time getting CIM setup but I think I've finally figured it out.  The only problem is, I'm still not "sure" if it's activated.  I ran the config utility and enabled CIM.  The ITA services are running as the CIM user and that user has local admin.  I'm not getting any errors...  But how do I know it's working?

More important perhaps is I'd really like to know what components/actions utilize CIM opposed to SNMP.

I'm also somewhat confused (in general, but trying to take it one step at a time ;)) about whether or not each "managed" station requires this CIM user to have administrative rights as well.  It does on the management station, but none of the managed ones.

Thank you very much for any replies.  Just trying to get a grip on all this...