The Army National Guard (ARNG), in conjunction with the Air National Guard, are the United States federal and state military reserve force. They are simultaneously part of two different organizations, the National Guard of the Several States, Territories and the District of Columbia (also referred to as the Militia of the United States), and the National Guard of the United States. The Army National Guard is divided into subordinate units stationed in each of the 50 states, three territories, and the District of Columbia, and operates under their respective governors.