The electromagnetic spectrum is the name we use when we talk about different types of radiation as a group. The parts of the electromagnetic spectrum, arranged from highest to lowest energy are: gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves.
All the parts of the electromagnetic spectrum are the same thing—radiation. Radiation is made up of a stream of photons—particles without mass that move in a wave pattern all at the same speed, the speed of light. Each photon contains a certain amount of energy.
