What is the meaning of subordinate unified command?

(DoD) A command established by commanders of unified commands, when so authorized by the Secretary of Defense through the Chairman of the Joint Chiefs of Staff, to conduct operations on a continuing basis in accordance with the criteria set forth for unified commands. A subordinate unified command may be established on an area or functional basis. Commanders of subordinate unified commands have functions and responsibilities similar to those of the commanders of unified commands and exercise operational control of assigned commands and forces within the assigned operational area. Also called subunified command. See also area command; functional component command; operational control; subordinate command; unified command.