Summary of electromagnetic spectrum
All electromagnetic waves can travel through vacuum. They all travel at the speed of 3 X 10^8 m/s in vacuum and very close to this value through air.
In other materials however, they travel a bit more slower. Each selection of the electromagnetic spectrum has is own uses and features:
The higher the frequency, the higher the energy of the radiation. Therefore radio waves have the lowest energy and gamma radiation has the highest energy within the spectrum.