it depends on the tradition.
Correllian Wicca Tradition for example
Outer court- people who are not members of the clergy
1st degree- Priest/ess and first level of clergy status, can do minor rituals such as a minor funeral rite or minor wiccaning
2nd degree-Priest/ess (this is the second level of clergy)
3rd degree- Priest/ess can do marriages, funerals, run their own temple, be elders, or hold office positions.
Shrine/Temple heads - leaders of specific temples, usually 3 degree clergy
Officers (same ranking as elders) - persons who hold traditioin wide offices such as first elder & first director
elders (3rd degree)- distinguished members appointed to elder council due to personal merit
Joint Heads- 1st Priest/ess
Chancellor- the chief executive officer
So like I said , it really depends on the tradition. The above is just merely an example, and just the very very bare min of what each level is and/or does.