Reserve Duty refers to a military service commitment where individuals, often civilians, are trained and available to serve in the armed forces when needed. These reservists typically have other jobs or responsibilities but can be called upon during emergencies, conflicts, or for training exercises. Reservists play a crucial role in supporting the active-duty military, providing additional manpower and specialized skills. They may serve in various branches, such as the Army, Navy, or Air Force, and their training ensures they are prepared to assist in national defense when required.