Marine Corps Gen. Joseph F. Dunford, chairman of the Joint Chiefs of Staff, addresses the APEX Senior Executive Orientation at the Pentagon, March 12, 2018. The two-week course provides new executives in the DoD with an understanding of the structure and processes of the Office of the Secretary of Defense, the Combatant Commands, the Joint Staff and the military departments. DoD photo by Navy Petty Officer 1st Class Dominique A. Pineiro