In a navy, a rate, rating or bluejacket is a junior enlisted member of that navy who is not a warrant officer or commissioned officer. Depending on the country and navy that uses it, the exact term and the range of ranks that it refers to may vary.
In the Royal Navy and other navies in the Commonwealth, rate and rating are interchangeably used to refer to an enlisted member of the navy who is ranked below warrant officers and commissioned officers but may include petty officers and chief petty officers.
The term comes from the general nautical usage of rating to refer to a seaman's class or grade as recorded in the ship's books. The system of conferring authority on sailors in the Royal Navy evolved through the recognition of competence: landsman, ordinary seaman, able seaman, through to the appointment of authority as a petty officer.
The general structure now used breaks down into four major groupings:
In the United States Navy, the term bluejacket is used instead to refer enlisted sailors that rank below a chief petty officer. Bluejacket derives itself from an item of clothing that was worn by junior enlisted sailors before 1886. It is used especially when the sailors are deployed ashore as infantry.