Close air support

Close air support is defined, by the U.S. Department of Defense, as Air action by fixed- and rotary-wing aircraft against hostile targets that are in close proximity to friendly forces and that require detailed integration of each air mission with the fire and movement of those forces.

It is distinguished from battlefield air interdiction, which attacks forces that are not in close proximity to friendly units, but are a potential threat to those units, or support the attacking forces.