Users Logged in Graph

This is a pretty general question, exactly what/how does the “Users Logged In” graph measure for servers?

I’ve got one which has gone up quite a lot and looking find the cause, as I’m pondering if it’s down to LDAP requests which have been plugged in to sync with some connected software, or something else.

It’s data from hrSystemNumUsers in HOST-RESOURCES-MIB. What your system sends back is down what snmp daemon it uses and what data is sent back from it.