Autopilots in modern complex aircraft are three-axis and generally divide a flight into taxi, take-off, ascent, level, descent, approach and landing phases. Autopilots exist that automate all of these flight phases except the taxiing. An autopilot-controlled landing on a runway and controlling the aircraft on rollout (i.e. keeping it on the centre of the runway) is known as a CAT IIIb landing or Autoland, available on many major airports’ runways today, especially at airports subject to adverse weather phenomena such as fog. Landing, rollout and taxi control to the aircraft parking position is known as CAT IIIc. This is not used to date but may be used in the future. An autopilot is often an integral component of a Flight Management System, according to Wiki.
Autopilot is system used to guide a vehicle without human assistance.
Autopilot is designed to perform some of the tasks of the pilot. The autopilot of an aircraft is sometimes referred to as “Naked lee”. Modern autopilots use computer software to control the aircraf. Computer will read the flight’s current position and control the Flight Control System to guide the aircraft.