What are the traditional roles and mission of each branch of service called?

The traditional roles and missions of each branch of service are referred to as functions. This designation signifies the specific responsibilities and operational capabilities that each military branch is designed to fulfill within the framework of the overall defense strategy. Each branch—such as the Army, Navy, Air Force, and Marine Corps—has unique functions that reflect its purpose, operational focus, and the type of warfare for which it is best equipped. For instance, the Air Force's primary functions revolve around air and space dominance, global strike, and rapid global mobility, showcasing the distinct nature of its role compared to other services.

The other terms like departments, responsibilities, and capacities do not accurately capture the concept of established roles and missions as systematically defined within the structure of the military. While they relate to the organization of the military and its operations, they do not specifically embody the comprehensive understanding of the respective functions of each service branch. Thus, identifying these roles as functions is essential for understanding how each branch operates within the larger context of national defense.