Satellite television is a system of delivering television programmingusing signals relayed from communication satellites. The signals are received via an outdoor parabolic reflector antenna usually referred to as a satellite dishand a low-noise block downconverter (LNB). A satellite receiver then decodes the desired television programme for viewing on a television set. Receivers can be external set-top boxes, or a built-in television tuner. Satellite television provides a wide range of channels and services, especially to geographic areas without terrestrial television or cable television.