The New York City Police Commissioner is the head of the New York City Police Department. The Commissioner is appointed by the Mayor, and serves at the Mayor's pleasure. The Commissioner is responsible for the day-to-day operation of the department as well as the appointment of deputies and subordinate officers. Commissioners are civilian administrators, and they and their subordinate deputies are civilians under an oath of office, not uniformed members of the force who are sworn officers of the law. There is a separate position of Chief of Department, the holder of which serves as the senior sworn uniformed member of the force.