An airline hub is an airport that an airline uses as a transfer point to get passengers to their intended destination. It is part of a hub and spoke model, where travelers moving between airports not served by direct flights change planes en route to their destinations. Many hubs of the airlines are also situated at airports in the cities of the respective head offices. Some airlines may use only a single hub, while other airlines use multiple hubs. Hubs are used for both passenger flights as well as cargo flights. Many airlines also utilize focus cities, which function much the same as hubs. Airlines may also use secondary hubs, a non-technical term for large focus cities. For most non-US airlines, it is more technically correct to use the term home base rather than hub as a majority of their flights are international and the so-called hubs are simply their home countries' largest airports, such as Dubai International Airport for Emirates Airline or Dublin Airport for Aer Lingus. Indeed, the application of the term hub in such contexts is only recently popularized by American airline industry analysts and often contested by local commentators.
