A more thorough explanation:

The Office of Protocol is a unit within the U.S. Department of State that provides guidance and advice to high-ranking U.S. officials on matters of custom and decorum. This includes planning and hosting state dinners and other events, particularly those involving foreign heads of state and diplomats. The Chief of Protocol is responsible for managing the office.

For example, if the President of the United States is hosting a state dinner for a foreign leader, the Office of Protocol would be responsible for ensuring that the event is planned and executed in a manner that is respectful and appropriate for both parties. This might include coordinating seating arrangements, menu planning, and other logistical details.

The Office of Protocol also manages the Blair House, which is a residence in Washington, D.C. that is often used to host diplomatic visitors. The Chief of Protocol oversees the management of the Blair House and ensures that it is maintained to a high standard.