An airliner is a large airplane designed specifically to carry passengers on scheduled flights between cities and countries. When your family flies on vacation or when businesspeople travel for work, they're almost certainly flying on an airliner. These are the big jets you see lined up at airport terminals, with rows of seats inside and space for luggage below.

Airlines like United, Delta, American, and Southwest operate fleets of airliners, flying millions of passengers every year. A typical airliner might carry anywhere from 100 to over 500 people, depending on its size. The Boeing 747, one of the most famous airliners ever built, has two decks and can seat more than 400 passengers.

The word distinguishes these passenger planes from other types of aircraft. A small private plane that seats four people isn't an airliner. A military jet fighter isn't an airliner. A cargo plane that carries only packages and freight isn't an airliner either (though many airliners are converted to carry cargo after years of passenger service).

Modern airliners are marvels of engineering, flying at speeds around 500 to 600 miles per hour and cruising at altitudes where the air is thin and cold. They've made it possible for ordinary people to cross oceans in hours rather than weeks, connecting the world in ways that would have seemed like magic to earlier generations.