 Commercial airliners are designed for carrying a passenger or cargo payload, long range and greater fuel efficiency where as fighter jets are designed to perform high speed maneuvers and provide close support to ground troops.Some aircraft have specific missions, for instance, amphibious airplanes have a unique design that allows them to operate from both land and water, some fighters, like the Harrier Jump Jet, have VTOL (Vertical Take-off and Landing) ability, helicopters have the ability to hover over an area for a period of time.The purpose may be to fit a specific requirement, e.g.