The Department of the Air Force is a branch of the United States Armed Forces responsible for aerial and space operations. It was established in 1947 and is one of the three military departments under the Department of Defense. The Air Force's primary mission is to defend the nation through control and exploitation of air and space. The Department is led by the Secretary of the Air Force, who oversees its operations, budget, and personnel. The Air Force includes various components, such as the Active Duty, Air National Guard, and Air Force Reserve, working together to ensure national security and support military objectives.