The U.S. Air Force is a military service organized within the Department of the Air Force, one of the three military departments of the Department of Defense.
The United States Air Force (USAF) is the aerial and space warfare service branch of the United States Armed Forces and one of the seven American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the U.S. Armed Forces on 18 September 1947 under the National Security Act of 1947. It is the most recent branch of the U.S. Armed Forces to be formed. The USAF is the largest and one of the most technologically advanced air forces in the world. The service articulates its core functions as Nuclear Deterrence Operations, Special Operations, Air Superiority, Global Integrated ISR, Space Superiority, Command and Control, Cyberspace Superiority, Personnel Recovery, Global Precision Attack, Building Partnerships, Rapid Global Mobility and Agile Combat Support.