The mission of the Navy is to maintain, train and equip combat-ready Naval forces capable of winning wars, deterring
aggression and maintaining freedom of the seas.

The U.S. Navy was founded on 13 October 1775, and the Department of the Navy was established on 30 April 1798. The Department of the Navy has three principal components: The Navy Department, consisting of executive offices mostly in Washington, D.C.; the operating forces, including the Marine Corps, the reserve components, and, in time of war, the U.S. Coast Guard (in peace, a component of the Department of Homeland Security); and the shore establishment.

The use of the word "rank" for Navy enlisted personnel is incorrect. The term is "rate." The rating badge is a combination of rate (pay grade, as indicated by the chevrons) and rating (occupational specialty, as indicated by the symbol just above the chevrons).

The insignia here represents a Petty Officer First Class (the rate) who is a Boatswain's Mate (the rating). A rating badge is worn on the left upper sleeve of all uniforms in grades E-4 through E-6. Chief Petty Officers (E-7 through E-9) wear collar devices on their white and khaki uniforms, and rating badges on their Service Dress Blues.

Navy officers wear their rank devices in different places on their uniforms, depending upon the uniform. The three basic uniforms and the type of rank devices are: khakis (a working uniform) — pins on the collar; whites — stripes on shoulder boards; and, blues — stripes sewn on the lower sleeve. Shoulder boards are also worn on bridge coats and reefers. A chart of the officer ranks is hyperlinked from the ensign's bar at the left.