Structure of the United States Air Force
The structure of the United States Air Force refers to the unit designators and organizational hierarchy of the United States Air Force, which starts at the most senior commands. The senior headquarters of the Department of the Air Force (DAF) consists of distinct staffs in the Pentagon: the Secretariat or SAF Staff and the Headquarters Air Force or HAF Staff.
Source: Wikipedia — Structure of the United States Air Force (CC BY-SA 4.0)