ADMINISTRATIVE
FLIGHT:
Two or more airplanes form a "flight." In combat, a flight usually consists of four or more planes that fly in pairs, trios, or fours. One plane, the flight leader, contains the flight commander who directs the operations of the entire flight.

SQUADRON:
The squadron usually consists of two or more flights. The squadron commander gives orders to the flight commanders rather than to the commanders of the individual planes. The squadron is the smallest air force unit that has both tactical and administrative duties. Each squadron includes ground personnel whose duties are to administer and furnish the ground services.

GROUP:
The group usually consists of two to four squadrons and a group headquarters. The group may be both tactical and administrative. All squadrons in a particular group fly the same type of plane. Groups, like squadrons, are categorized by type of plane, like a heavy bomber group, light bomber group or fighter group. All squadrons of a group train together and the group usually moves and fights as a unit.

WING:
The basic Air Force combat unit is the wing. The wing has always been the prime war fighting instrument.

There is one basic rule for wing organization: one base, one wing, one boss. The installation commander commands the wing, the base and all the local resources associated with it.

NUMBERED AIR FORCE (NAF):
Two or more wings are usually grouped with auxiliary units to form a Numbered Air Force -- a large striking organization specializing in one major category of air strength. The NAF is the senior war-fighting echelon of the Air Force. War-fighting NAFs conduct theater operations with assigned and attached forces.

COMBAT
AIR EXPEDITIONARY FORCE (AEF)/ AIR AND SPACE EXPEDITIONARY TASK FORCE (ASETF):
The AEF was designed to respond to the increasing number of situations that call for worldwide deployments.

Under the AEF concept, almost all of the Air Force -- active, Reserve and Guard -- will be divided into 10 force packages, each with a cross-section of Air Force weapon systems drawn from geographically separated units. Each AEF will have about 175 aircraft.

These AEF packages are designed to respond within 72 hours of any unexpected contingency -- and will be trained and tailored to meet commanders' needs in a wide range of operations.

AEROSPACE EXPEDITIONARY WING:
There are two Aerospace Expeditionary Wings -- the 366th Wing at Mountain Home Air Force Base, Idaho, and the 4th Fighter Wing at Seymour Johnson AFB, N.C. The two wings rotate "on-call" responsibilities and respond to crises as they occur throughout the world.

An AEW normally is composed of the wing command element and several groups. Where possible, the AEW is formed from units of a single wing.

AIR EXPEDITIONARY GROUP:
An Air Expeditionary Group (AEG) is a deployed independent group attached to an Air and Space Expeditionary Task Force or in-place Numbered Air Force. An AEG is composed of a slice of the wing command element and some squadrons. Since Air Force groups are organized without significant staff support, a wing slice is needed to provide the command and control for Air Expeditionary Forces smaller than a normal wing. Where possible, the AEG is formed from units of a single wing. The AEG commander, normally a colonel, will report to the Air and Space Expeditionary Task Force/in-place Numbered Air Force commander.

-- By Raven Tyler, Online NewsHour