Mission Command
Mission command is a command philosophy that uses decentralization to survive uncertainty and time pressure [jointchiefs2016dictionary].
In joint terminology, mission command is defined as the conduct of military operations through decentralized execution based upon mission-type orders. In Army doctrine, mission command is defined more explicitly as an approach to command and control that empowers subordinate decision making and decentralizes execution appropriate to the situation. The overlap is real, but the difference matters: one is a method of conducting operations; the other is a doctrinal approach to C2 that emphasizes specific principles and practices.
References
[jointchiefs2016dictionary] Joint Chiefs of Staff. (2016). Department of Defense Dictionary of Military and Associated Terms. Joint Publication 1-02 (as amended through 15 Feb 2016).
[usarmy2019missioncommand] Randi Stenson, Ted Crisco. (2019). Army updates mission command doctrine. U.S. Army (23 Aug 2019).