The DoD components include "the Office of the Secretary of Defense, the Military Departments, the Chairman of the Joint Chiefs of Staff and the Joint Staff the combatant commands, the Office of the Inspector General of the Department of Defense, the Department of Defense agencies, Department of Defense field activities, and all other organizational entities in the Department of Defense."
Office of the Chairman of the Joint Chiefs of Staff. (2019). Dictionary of Military and Associated Terms. Washington DC: The Joint Staff.