An airport is a location with the facilities for airplanes to take off and land. Millions of passengers visit airports to travel abroad by booking a flight with an airline operator. Airport staff consist of pilots and flight-attendants as well as workers within airport security and passport control. In the event of delay rather than waiting at airport terminals, travelers may browse through the various shops and eateries and buy through the airport duty-free. Air-traffic control is responsible for the coordinated flights at the airport.