The United States Navy (USN) is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest, most powerful navy in the world,with the highest combined battle fleet tonnage. The U.S. Navy has the world's largest aircraft carrier fleet, with ten in service, four in the reserve fleet,and three new class carriers under construction. The service has 325,143 personnel on active duty and 107,355 in the Navy Reserve. It has 271 deployable combat ships and more than 3,600 aircraft in active service as of June 2015