Satellite television is television delivered by the means of communications satellites, as compared to conventional terrestrial television - which is broadcast over radio waves originating from several independent, ground-based televison stations - and cable television - which is distributed by underground coaxial cables. In many areas of the world, satellite television services supplement older terrestrial signals, providing a wider range of channels and services, including subscription-only services. It is very popular although normally to receive satellite television you must purchase a receptor such as Sky dish and digibox, Freesat, Virgin Media etc.