A helicopter is an aircraft which is lifted and propelled by one or more horizontal rotors (propellers).
Helicopters are classified as rotary-wing aircraft to distinguish them from conventional fixed-wing aircraft.
Compared to conventional fixed-wing aircraft, helicopters are much more complex, more expensive to buy and operate, relatively slow, have shorter range and restricted payload.
The compensating advantage is maneuverability: helicopters can hover in place, reverse, and above all take off and land vertically.
Subject only to refueling facilities and load/altitude limitations, a helicopter can travel to any location, and land anywhere with enough space (approximately twice the area of the rotor disk).