This is also the wavelength region where the Sun emits most of its electromagnetic energy. Even though our experience with low frequency radiation such as radio waves or microwaves is dramatically different from our experience with X-rays, all electromagnetic radiation is fundamentally the same.
All electromagnetic radiation travels at the speed of light.
Radio radiation is made up of low energy photons. The energy of a photon is directly proportional to the frequency of the radiation, so radio waves have low frequency. This radiation is spread over some region of the electromagnetic spectrum. The energy of any object peaks at a wavelength which is dependent on the temperature of the object. Cooler objects emit most of their energy at lower energies, while the hotest objects emit most of their energy at the highest frequencies.