It is a wireless way of communication that uses radio waves to broadcast to an audience. There are several ways of using this popular kind of communication, such as: via cable radio, local wire television networks, satellite radio, and internet radio via streaming media on the Internet. Radio programs are similar to the ones that are done by the TV broadcast because they have to fill all the available spaces with programs and music; they gain money thanks to advertising. There are different kinds of radios, for example: the amateur radios (it is a non-commercial private kind of communication with the purpose of recreation by using a designed radio band), pirate radio (a broadcasting that is not sanctioned by the laws of the originating countries, it has many purposes: entertainment, political reasons, etc) and professional radio (it is run by broadcasting professionals.)