Structure of the United States Navy

The structure of the United States Navy consists of four main bodies: the Office of the Secretary of the Navy, the Office of the Chief of Naval Operations, the operating forces (described below), and the Shore Establishment. == Office of the Chief of Naval Operations == The chief of naval operations presides over the Navy Staff, formally known as the Office of the Chief of Naval Operations (OPNAV).

Source: Wikipedia — Structure of the United States Navy (CC BY-SA 4.0)