Separate brigades are commanded by a Brigadier General. Again, they are supported by field artillery battalions, aviation units and smaller combat, combat service, and combat service support units. A division commander may establish the organization of their brigades as required to accomplish each mission. Separate brigades and cavalry regiments normally have a fixed organization. They are capable of performing any tactical mission and designed to be largely self-sustaining.
Divisions are the basic unit of maneuver at the tactical level.
Armored, mechanized infantry, light infantry, airborne and air assault divisions are all presently in the force. They possess great flexibility. Divisions perform major tactical operations for the corps and can conduct sustained battles. Corps are tailored for the theater and mission for which they are deployed. Corps plan and conduct major operations and battles.