Obedience is the visible yield. Submission is the hunger beneath it. One is a posture. The other is a possession. To obey is to act in accordance with a directive. To submit is to be rewritten by the gravity of the one who commands. The difference is not semantic — it is anatomical, spiritual, mythic. Obedience lives in the muscles. Submission lives in the marrow.
The obedient will kneel when told. The submissive has no choice.