There was a good message left by Boss_of_bosses in January that may help clear this up. He found a site detailing the mob hierarchy, and I've copied some of his message below:

Capo / Don / "Godfather"(Boss):
The Don is the head of the family, no one can call the shots over his decisions. He is also only 1 of 2 people who can initiate someone into the family. Since his rank gives him the authority to give the oath to new members and make them sgarrista.. He also has the authority to give people their positions and ranks.

Sotto Capo / Capo Bastone (Underboss):
The Underboss is appointed by the Don. He is the second in command of the entire operation. He is usually the leader of "day-to-day" functions..Hes the muscle on the street. His word should go unchallenged by everyone except the don. He is basicly the top dog when it comes to the work on the street. The Don goes to him for "orders" and "jobs". He is also to see to it that the Caporegimes stay in check. Underboss is the only other person who has the authority to swear in new members, but he must report them to the don.

Consigliere(Counselor / Advisor):
The Consigliere is voted by the whole family(made members). In theory, the consigliere is the same rank as the underboss. Yet the consigliere has no power in the "day-to-day" operations. He is only there to advise and sometimes question. He is the equal rank of underboss but does not have the authority to give any orders. His job is to advise on all of the don's decisions and some of the underboss's. He is the only one in the family who is allowed to speak his mind on all important matters and even question the don, yet can not override him.