The basic layout of a commercial airport is designed as a flow-through system consisting of two primary zones: Landside and Airside, separated by a security barrier. The Landside zone includes the "Departures" hall (where check-in counters and baggage drops are located) and the "Arrivals" hall (where baggage claim carousels and ground transportation like taxis and buses are found). Once passengers pass through the Security Screening Checkpoint, they enter the Airside zone. This area is composed of the Concourse, which houses departure gates, duty-free shops, and lounges. The layout of the concourses can vary; common designs include the "Pier" (long walkways extending from a central hub), the "Satellite" (a separate building reached by a tunnel or train), or the "Linear" layout. Outside, the Ramp (or Apron) is where planes are parked and serviced, leading to the Taxiways and finally the Runways. This design ensures that passengers move in a logical sequence from the street to the aircraft seat while maintaining strict security and operational efficiency for the ground crews and air traffic control.