As a learner of Physics I am very much interested to know about the EM waves and EM field. As far as I know, the Electric filed and Magnetic filed are perpendicular to each other and that makes the EM field propagation. EM waves are fluctuations in that field. Radio waves, micro waves, IR,visible light,UV, X-ray, and Gamma rays are EM waves at various frequncy ranges. I want to know why do the frquency ranges vary? Which makes them to vary and how? are the electric and magentic fields are spread all over the universe? are they fade away when getting farther away from matter?