Airport is a transport enterprise intended for air transportation of passenger and cargoes. It consists of landside and airside areas.
Landside area includes parking lots, tank farms, access roads, traffic control service, air station itself, and etc. Airside area comprises all areas accessible o aircraft, i.e. runways, taxiways, ramps, tank farms and others.
Access from landside areas to airside ones is tightly controlled at most airports.
Passengers on commercial flights access airside areas through terminals, where they can purchase tickets, clear security, check or claim luggage. Passengers can board aircraft through gate. The waiting areas for passengers are called concourses. This term is often used instead of terminal.
Airports depend on air traffic density and available facilities. Many airports have air traffic control located in tower. Such airports are called towered airports.
Airports with international flights have customs and immigration facilities.
International flights often require a higher level of physical security; in recent years many countries have adopted the same level of security not only for international but for domestic flights.