A pilot begins their training flying under Visual Meteorological Conditions (VMC) which means they must have sufficient visibility to fly the aircraft maintaining a visual reference from the terrain and other aircraft. An Instrument Rating allows the pilot to fly without reference to the ground and in Instrument Meteorological Conditions (IMC). This gives the pilot the ability to fly into areas of cloud and marginal weather and allows greater flexibility when flight planning. The Instrument Rating is also useful if pursuing a career in aviation as it is a requirement for most jobs. The instrument training may be conducted in either a single engine aircraft (group 3) or a multi engine aircraft (group 1). A group 1 is a requirement for an Airline Transport Pilot Licence.