The United States Navy

The Navy falls under the administration of the Department of the Navy, under civilian leadership of the Secretary of the Navy (SECNAV). The most senior naval officer is the Chief of Naval Operations (CNO), a four-star admiral who is immediately under and reports to the Secretary of the Navy. At the same time, the Chief of Naval Operations is one of the Joint Chiefs of Staff, which is the second-highest deliberatory body of the armed forces after the United States National Security Council, although it only plays an advisory role to the President and does not nominally form part of the chain of command. The Secretary of the Navy and Chief of Naval Operations are responsible for organizing, recruiting, training, and equipping the Navy so that it is ready for operation under the command of the Unified Combatant Commanders.
• Operating forces
There are nine components in the operating forces of the U.S. Navy: the United States Fleet Forces Command, United States Pacific Fleet, United States Naval Forces Central Command, United States Naval Forces Europe, Naval Network Warfare Command, Navy Reserve, United States Naval Special Warfare Command, Operational Test and Evaluation Force, and Military Sealift Command. Fleet Forces Command controls a number of unique capabilities, including Military Sealift Command, Naval Expeditionary Combat Command, and Navy Cyber Forces.
The United States Navy has seven active numbered fleets — Second, Third, Fifth, Sixth, Seventh Fleet and Tenth Fleets are each led by a three-star vice admiral, and the Fourth Fleet is led by a rear admiral. These seven fleets are further grouped under Fleet Forces Command (the former Atlantic Fleet), Pacific Fleet, Naval Forces Europe-Africa, and Naval Forces Central Command, whose commander also doubles as Commander Fifth Fleet; the first three commands being led by four-star full admirals. The United States First Fleet existed after the Second World War from 1947, but it was redesignated Third Fleet in early 1973. In early 2008, the Navy reactivated the United States Fourth Fleet to control operations in the area controlled by Southern Command, which consists of US assets in and around Central and South America.