User: Why do people fly on airplanes?
Assistant: People fly on airplanes to go between places faster.  Driving is an alternative to flying but when time is an issue flying is the quickest way to get to your destination.  Flying is also necessary when you need to get to an island or another continent which is not attached to the continent where you live.  Taking a boat may be too costly and long in some cases even if you don't like flying.  Flying is used to take trips, visit family and friends, meeting new people, interacting with co-workers, and sight-seeing.