Non-ionizing radiation (or, esp. in British English, non-ionising radiation) means any type of electromagnetic radiation that does not carry enough energy to ionize atoms or molecules - that is, to completely remove an electron from an atom or molecule.
The composition of this radiation can vary depending on what may be ionized. Visible light, near ultraviolet, infrared, microwave and radio waves are all examples of non-ionizing radiation, though visible and near ultraviolet can also ionize some molecules. The light from the Sun that reaches the earth is largely composed of non-ionizing radiation, with the notable exception of some ultraviolet rays. However, most ionizing radiation is filtered out by the atmosphere.