There is the relationship of PM (profile manager, full member) and Guest and Family member as well as Newcomer (inexperienced) and Oldster (experienced)
Other relationships are parent/child, step-parent and spousal, as well as sibling, half-sibling, step-sibling and so forth -- all these in their variations are connections by blood or by marriage
There are relationships which are hierarchical -- boss/employee, teacher/student, judge/lawyer, cop/criminal, owner/domestic pet, and so forth