With the approval of the Governor, the Secretary shall appoint a deputy secretary. The deputy secretary serves at the pleasure of the Secretary. The deputy secretary is entitled to the salary provided in the State budget. The deputy secretary has the duties provided by law or delegated by the Secretary. The Secretary may employ a staff in accordance with the State budget. Each assistant secretary, staff assistant to the Secretary, and professional consultant is appointed by and serves at the pleasure of the Secretary. Unless otherwise provided by law, the Secretary shall appoint and remove all other staff in accordance with the provisions of the State Personnel and Pensions Article. The appointment or removal of staff of any unit in the Department is subject to the approval of the Secretary. As to any unit in the Department, the Secretary may delegate this authority to the head of that unit.