Examples of radiation include gamma radiation and X-rays. Gamma radiation and X-rays are recognized as highly penetrating forms of electromagnetic radiation. Both of these types of radiation are capable of traveling several feet through the air and several inches into human tissue.
Gamma radiation and X-rays are able to easily penetrate most materials, and machines that produce this type of radiation are a direct hazard to humans. However, X-rays are used for medical purposes. Gamma radiation and X-rays are similar, differing only in the amount of energy produced. These two types of radiation are more energetic than other common forms of electromagnetic radiation produced by radio waves, visible light and ultraviolet light.