The United States Navy

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.
• Shore establishments
Shore establishments exist to support the mission of the fleet through the use of facilities on land. Among the commands of the shore establishment, as of April 2011, are the Naval Education and Training Command, the Naval Meteorology and Oceanography Command, the Space and Naval Warfare Systems Command, the Naval Facilities Engineering Command, the Naval Supply Systems Command, the Naval Air Systems Command, the Naval Sea Systems Command, the Bureau of Medicine and Surgery, the Bureau of Naval Personnel, the United States Naval Academy, the Naval Safety Center, the Naval Strike and Air Warfare Center, and the United States Naval Observatory. Official Navy websites list the Office of the Chief of Naval Operations and the Chief of Naval Operations (CNO) as part of the shore establishment, but these two entities effectively sit superior to the other organizations, playing a coordinating role.