The Joint Chiefs of Staff (JCS) is a body of senior uniformed leaders in the United States Department of Defense who advise the Secretary of Defense, the Homeland Security Council, the National Security Council and the President of the United States on military matters. The composition of the Joint Chiefs of Staff is defined by statute and consists of the Chairman of the Joint Chiefs of Staff (CJCS), Vice Chairman of the Joint Chiefs of Staff (VCJCS), and the Military Service Chiefs from the Army, Marine Corps, Navy, Air Force, and the Chief of the National Guard Bureau, all appointed by the President following Senate confirmation. Each of the individual Military Service Chiefs, outside of their Joint Chiefs of Staff obligations, works directly for the Secretary of the Military Department concerned, i.e., Secretary of the Army, Secretary of the Navy, and the Secretary of the Air Force.