An airfield is the operational area where flight activities occur. While all airports contain an airfield, an airfield does not necessarily have the passenger terminals, cargo facilities, or paved runways required to be classified as an airport. It often refers to military bases or smaller general aviation strips.
The military airfield is closed to civilian traffic unless you declare an emergency.
Pilots often use airfield when talking specifically about the runway and taxiway environment, ignoring the terminal buildings.
Related terms
Runway
A defined rectangular area on a land aerodrome prepared for the landing and takeoff of aircraft.
Tarmac
The paved surface at an airport where aircraft park, load, and maneuver.
Landing strip
A basic, unpaved or temporary runway used for aircraft operations.
Apron
The paved area at an airport where aircraft are parked, loaded, refueled, or boarded.