Chief of staff
Chief of staff is an important adviser, aide, or coordinator for the executive or office holder. The Chief of staff is known as the highest-ranking member or senior aide.
The Chief of staff services an executive leader such as the President or head-of-state, a military commanding officer, an elected official, a business executive or a commission.
The position is usually appointed by the leader and serves on his behalf, conducting day-to-day duties such as dealing with inquiries from the legislative branch of government.