Helicopters are a type of rotorcraft, which are capable of vertical take off and landing. They are fitted with one or more rotors, which enable them to hover, and to move forward or backwards and laterally. Helicopters can operate from smaller space compared to fixed-wing aircraft which often require a runway. They often use helipads as landing areas, which can be part of airports and heliports, or can be located in isolated places. A helicopter deck can be part of large ships, and oil rigs, while helipads can sometimes located atop large skyscrapers.