noun
General term for an airport, used in both formal and casual contexts.
成田空港までバスで行きます。
I'll go to Narita Airport by bus.
空港で友達を迎えました。
I picked up my friend at the airport.
飛行場 is a more general term for an airfield or airstrip, often smaller and not necessarily for commercial flights, while 空港 specifically refers to a commercial airport with passenger facilities.
Compound of 空 (kuu, 'sky') and 港 (kou, 'port'), literally 'sky port'. A relatively modern coinage reflecting the concept of an airport as a port for aircraft.