Radiowaves are the oscillations of magnetic waves by varying the modulation to generate different signals which can be converted into information such as sound, video, or digital communication. As these waves pass through a conductor, an alternating current is generated and this can be converted into usable information.

Click on picture for source. <http://en.wikipedia.org/wiki/Radio>

As one could see from the picture above, radio waves are the the electromagnetic waves with wave lengthes between 1mm and 10 Mm. This converts to a frequency range of 300Ghz to 30Hz, respectively.