The Army, as one of the three military departments (Army, Navy and Air Force) reporting to the Department of Defense, is composed of two distinct and equally important components: the active component and the reserve components. The reserve components are the United States Army Reserve and the Army National Guard.

Regardless of component, The Army conducts both operational and institutional missions. The operational Army consists of numbered armies, corps, divisions, brigades, and battalions that conduct full spectrum operations around the world. (Operational Unit Diagram and descriptions) The institutional Army supports the operational Army. Institutional organizations provide the infrastructure necessary to raise, train, equip, deploy, and ensure the readiness of all Army forces. The training base provides military skills and professional education to every Soldier?as well as members of sister services and allied forces. It also allows The Army to expand rapidly in time of war. The industrial base provides world-class equipment and logistics for The Army. Army installations provide the power-projection platforms required to deploy land forces promptly to support combatant commanders. Once those 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.

Depicted below is a top-level look at how The Army is organized. All units, installations and facilities within The Army either report to one of the Army Major Commands or directly to the Headquarters Department of the Army (HQDA) Staff.

Mission
The Army?s mission is to fight and win our Nation?s wars by providing prompt, sustained land dominance across the full range of military operations and spectrum of conflict in support of combatant commanders. We do this by:

? Executing Title 10 and Title 32 United States Code directives, to include organizing, equipping, and training forces for the conduct of prompt and sustained combat operations on land.

? Accomplishing missions assigned by the President, Secretary of Defense and combatant commanders, and Transforming for the future.