Boss: The undisputed head of a Crime Family. Represents his family on the Commission.
Consigliere: A counselor and adviser to the boss. The consigliere is a trusted friend and confidant, usually considered to be the boss' left hand.
Underboss: A boss' right hand and powerful second-in-command, the most senior of all the family's caporegimes; often when a boss is incarcerated, the underboss will take over day to day operations as "street boss" or "acting boss".
Caporegimes: Captains, or Capos, these are senior ranking members of a family who head up a crew consisting of soldiers and associates alike.
Soldiers: Also known as a "made man", soldiers are the lowest members of a crime family but still command respect in the organization. To become made, soldiers are required to take an oath of silence, called the Omerta. It is usually also a requirement that member being inducted have committed murder for the family.
Associates: Also know as "connected guys", these individuals have not been made and are part of a crew, free to commit crimes under the protection and direction of made members. They are expected to remit a share of their illegal proceeds to their direct made superiors, a tradition which works all the way up the tree.