ILS, or Instrument Landing System, is a ground-based navigation aid that helps pilots land aircraft safely, especially in low visibility conditions. It provides precise guidance by using radio signals to direct the aircraft along a specific approach path to the runway. The system consists of two main components: the Localizer, which helps align the aircraft with the runway centerline, and the Glide Slope, which provides vertical guidance for the correct descent angle. ILS is widely used in commercial aviation, enhancing safety and efficiency during landings.