The National Guard Bureau is a joint activity of the United States Department of Defense. It serves as a liaison between the federal government and the state National Guards, ensuring that they are prepared for both state and federal missions. The Bureau oversees the training, readiness, and administration of the National Guard, which consists of both the Army National Guard and the Air National Guard. Additionally, the National Guard Bureau plays a crucial role in coordinating support during emergencies, such as natural disasters. It helps facilitate the mobilization of National Guard units when needed, ensuring that they can respond effectively to various situations, including domestic crises and overseas deployments.