General
The major US armed services – the Army, Navy, and Air Force – are composed of two distinct and equally important components: the active component and the reserve component.
Regardless of component, the armed services conduct both operational and institutional missions. The operational Army, for instance, conducts full spectrum operations around the world. The institutional Army provides the infrastructure necessary to raise, train, equip, deploy, and ensure the readiness of all Army units. Once operational forces are deployed, the institutional Army provides the logistics needed to support them. Without the institutional Army, the operational Army cannot function. Without the operational Army, the institutional Army has no purpose[48].
Within the armed services there are several major commands, most organized functionally or geographically. Each major command is led by a four-star general[49].