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 capable 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, two in the reserve fleet, and three new class carriers under construction. The service has 328,186 personnel on active duty and 110,882 in the Navy Reserve. It has 272 deployable combat vessels and more than 3,700 aircraft in active service .