Kinds of airports

Airport pages on this site carry a label such as "large airport" or "seaplane base". Here is what the labels, and a few other common words, mean.

Large, medium and small

These labels come from OurAirports, the open data project behind this site. They describe how much traffic an airport handles, not the size of its land. A large airport has major airline service, usually with many flights a day. A medium airport has regular airline flights or is a busy regional or military field. A small airport has little or no airline service. The labels are set by volunteers and are a guide, not an official grade.

Scheduled service

An airport has scheduled service when airlines run regular, timetabled flights that the public can book. This site gives a full page to airports with scheduled service. Many more airfields have a code but are used only by private, charter, cargo, training or military flights.

International and domestic

An international airport has customs and immigration counters, so flights can arrive from other countries. A domestic airport handles flights within one country only. The word "international" in an airport's name is not always a sign of many foreign flights.

Hubs

A hub is an airport where an airline gathers passengers from many cities and sends them on to many others. Flying through a hub means changing planes, but it lets an airline connect hundreds of city pairs with far fewer routes. Dubai, Doha, Singapore and Frankfurt are well-known hubs.

Seaplane bases and heliports

A seaplane base is a stretch of water where aircraft with floats land and take off. They are common in places with many islands or lakes, such as the Maldives, Alaska and western Canada. A heliport is a landing place for helicopters only.

Airside and landside

Inside a terminal, landside is the public part before security, and airside is the part after security, where the gates are. Once you are airside you normally cannot come back out without going through checks again.