Close air support

In military tactics, close air support (CAS) is defined as air action by fixed or rotary-winged aircraft against hostile targets that are close to friendly ground or naval forces, and which requires detailed integration of each air mission with fire and movement of these forces.
Conversely, deep air support (DAS) is air action directed on objectives not in the immediate vicinity of friendly forces for the purposes of neutralizing and destroying enemy reserves and weapons, and for interfering with enemy command, supply, communications, and observations.
The determining factor for CAS is detailed integration, not proximity. CAS may need to be conducted far from friendly forces, if the mission requires detailed integration with the fire and movement of these forces. A closely related subset of air interdiction, battlefield air interdiction denotes interdiction against units with near-term effects on friendly units, but which does not require integration...