An airport terminal is a building at an airport. It is where passengers are able to get on and off aircraft. Inside the terminal, passengers can buy tickets, leave or pick up their luggage, and be checked by security staff. The buildings that provide access to the airplanes through gates are usually called concourses.

While often used interchangeably, an airport and a terminal represent two different scales of aviation infrastructure. An airport is the entire facility, encompassing the runways, taxiways, control towers, hangars, parking lots, and the land itself. It is the geographic entity (like JFK or Heathrow). A terminal, on the other hand, is a specific building within the airport where passengers begin and end their journeys. The terminal houses the "human" services: check-in counters, security checkpoints, baggage claims, and retail shops. Large airports usually have multiple terminals (e.g., Terminal 1, Terminal 2) to handle different airlines or domestic vs. international flights. You might also encounter "concourses," which are the long hallways branching off from a terminal that lead to the individual boarding gates. Essentially, the airport is the whole "campus," while the terminal is the specific building where you interact with the airline staff and clear security.