Within the terminal, passengers purchase tickets, transfer their luggage, and go through security. The buildings that provide access to the airplanes (via gates) are typically called concourses. However, the terms "terminal" and "concourse" are sometimes used interchangeably, depending on the configuration of the airport.
Smaller airports have one terminal while larger airports have several terminals and/or concourses. At small airports, the single terminal building typically serves all of the functions of a terminal and a concourse.
Some larger airports have one terminal that is connected to multiple concourses via walkways, sky-bridges, or underground tunnels (such as Denver International Airport). Some larger airports have more than one terminal, each with one or more concourses (such as New York's JFK Airport). Still other larger airports have multiple terminals each of which incorporate the functions of a concourse (such as Dallas/Fort Worth International Airport).
According to Frommers, most airport terminals are built in a plain style, with the 'concrete boxes of the 1960s and '70s generally gave way to glass boxes in the '90s and '00s, with the best terminals making a vague stab at incorporating ideas of "light" and "air"'. However, some, such as Baghdad International Airport, are monumental in stature, while others are considered architectural masterpieces, such as Terminal 1 at Charles de Gaulle airport near Paris or Terminal 5 at New York's JFK Airport. A few are designed to reflect the culture of a particular area, some examples being the terminal at Albuquerque International Sunport in New Mexico, which is designed in the Pueblo Revival style popularized by architect John Gaw Meem, as well as the terminal at Bahías de Huatulco International Airport in Huatulco, Oaxaca, Mexico, which features some palapas that are interconnected to form the airport terminal.
Due to the rapid rise in popularity of passenger flight, many early terminals were built in the 1930s–1940s and reflected the popular art deco style architecture of the time. One such surviving example from 1940 is the Houston Municipal Airport Terminal. Early airport terminals opened directly onto the tarmac: passengers would walk or take a bus to their aircraft. This design is still common among smaller airports, and even many larger airports have "bus gates" to accommodate aircraft beyond the main terminal.
A pier design uses a small, narrow building with aircraft parked on both sides. One end connects to a ticketing and baggage claim area. Piers offer high aircraft capacity and simplicity of design, but often result in a long distance from the check-in counter to the gate (up to half a mile in the cases of Kansai International Airport or Lisbon Portela Airport's Terminal 1). Most large international airports have piers, including Chicago's O'Hare International Airport, Larnaca International Airport, Frankfurt International Airport, London Heathrow Airport, Amsterdam Schiphol Airport, Murtala Muhammed International Airport, Kuala Lumpur International Airport, Mérida International Airport, Bangkok International Airport, Mazatlan International Airport, Beirut International Airport, Hong Kong International Airport, Allama Iqbal International Airport, Tijuana International Airport, Rome Fiumicino Airport, Toronto-Pearson International Airport, Delhi International Airport, Fort Lauderdale–Hollywood International Airport and Miami International Airport.
A satellite terminal is a building detached from other airport buildings, so that aircraft can park around its entire circumference. The first airport to use a satellite terminal was London Gatwick Airport. It used an underground pedestrian tunnel to connect the satellite to the main terminal. This was also the first setup at Los Angeles International Airport, but it has since been converted to a pier layout. The first airport to use an automatic people mover to connect the main terminal with a satellite was Tampa International Airport, which is the standard today. Other examples include the following:
- Paris's Charles de Gaulle International Airport (Terminal 1) and London Gatwick Airport (South Terminal) both have circular satellite terminals.
- Orlando International Airport and Pittsburgh International Airport have multi-pier satellite terminals.
- Brussels Airport's Pier A is connected to the main building via underground tunnels and walkways.
- Zurich Airport's Gates E are connected with a subway.
- At Logan International Airport in Boston, Terminal A has two sections of gates, one of which is a satellite terminal connected by an underground walkway.
- Denver International Airport, General Mariano Escobedo International Airport, Cincinnati/Northern Kentucky International Airport, and Hartsfield-Jackson Atlanta International Airport have linear satellite terminals connected by central passages.
- London's third largest airport, Stansted, has one main terminal building with three linear satellite terminals all connected to the main terminal by an automated people mover. The airport is currently expanding by adding an additional satellite building.
- Kuala Lumpur International Airport has a cross-shaped satellite terminal which is used for international flights.
- Cancun International Airport Terminal 2 is an irregular terminal with two concourses, Main building and Satellite building, the latter one being the satellite terminal.
- Seattle-Tacoma International Airport has two rectangular satellite terminals connected by an automatic people mover system.
- Jinnah International Airport in Karachi has one main terminal, divided into two concourses: the Jinnah East Satellite Concourse, used for international flights, and the Jinnah West Satellite Concourse, used for domestic and some international flights.
- McCarran International Airport in Las Vegas has an X-shaped satellite terminal that is connected by two automatic people movers.
- Mariano Escobedo International Airport is the first and only airport in Mexico which has a completely satellite terminal. Terminal A is connected from Main to Satellite building via underground tunnels.
- London Heathrow Airport Terminal 5 has two satellite terminals, 5B, and 5C.
- Abu Dhabi International Airport
- Rome Fiumicino Airport has one satellite terminal, called T3G, connected by a Bombardier Innovia APM 100.
Some airports use a semicircular terminal, with aircraft parked on one side and cars on the other. This design results in long walks for connecting passengers, but greatly reduces travel times between check-in and the aircraft. Airports designed around this model include Charles de Gaulle International Airport (terminal 2), Chhatrapati Shivaji International Airport, Mumbai (terminal 2), Dallas/Fort Worth International Airport, Seoul's Incheon International Airport, Jakarta's Soekarno-Hatta International Airport, Toronto Pearson Airport, Kansas City Airport and Sapporo's New Chitose Airport.
One rarer terminal design is the mobile lounge, where passengers are transported from the gate to their aircraft in a large vehicle which docks directly to the terminal and the aircraft. Washington Dulles International Airport, Mexico City International Airport, and Mirabel International Airport have used this design.
A common-use facility or terminal design disallows airlines to have its own proprietary check-in counters, gates and IT systems. Rather, check-in counters and gates can be flexibly reassigned as needed.
Dubai International Airport, Dubai, United Arab Emirates, Terminal 3, became the largest single Terminal building in the world with an area of over (1,713,000 m²) when it opened on October 14, 2008. It can handle an excess of 60 million passengers.
Beijing, Hong Kong, Bangkok and Mexico City have the world's second, third, fourth and fifth largest single terminals (986,000 m2, 570,000 m2, 563,000 m2 and 542,000 m2) in Beijing Capital International Airport, Hong Kong International Airport, Suvarnabhumi Airport and Mexico City International Airport respectively.
Many small and mid-size airports have a single two or three-lane one-way loop road which is used by local private vehicles and buses to drop off and pick-up passengers.
An international airport may have two grade-separated one-way loop roads, one for departures and one for arrivals. It may have a direct rail connection by regional rail, light rail, or subway to the downtown or central business district of the closest major city. The largest airports may have direct connections to the closest freeway. There will be car rental agencies and taxi companies operating around the terminals. The Hong Kong International Airport has ferry piers on the airside to connect with ferry piers across the border. Dubai International Airport leads the latter in terms of design, comfort, and location.
- Check-in counters
- Retail stores and restaurants
- Busiest Airports – The Busiest Airports in the World. Geography.about.com. Retrieved on 2013-04-09.
- The 10 Worst Airport Terminals Slideshow at Frommer's. Frommers.com. Retrieved on 2013-04-09.
- World's 10 Most Beautiful Airport Terminals Slideshow at Frommer's. Frommers.com. Retrieved on 2013-04-09.
- McGraw-Hill Construction | ENR – Next Phase of Baggage Screening Goes In-line, Out ofView. Enr.construction.com (2003-12-15). Retrieved on 2013-04-09.
- New Terminal 3 to evoke 'tranquillity' – The National. Thenational.ae (2011-07-22). Retrieved on 2013-04-09.