Radio waves, infrared "rays" from heat lamps, the waves that heat food in a microwave oven, ultraviolet rays, and X-rays are all considered types of what kind of energy.

They are all considered to be electromagnetic radiation. In this kind of radiation or energy, electric and magnetic fields vary at the same time, creating rates or frequencies that determine the different types of "rays" and how much energy each wave carries - the higher the frequency is, the more energy it bears.