The word radiation conjures up images of the atomic bomb being dropped on Hiroshima or the Chernobyl nuclear power plant disaster. Our society has a strong, and not unreasonable, fear of nuclear radiation.
These fears are founded on a bedrock of experience. It starts with Marie Curie, the scientist who discovered the property of radioactivity and subsequently died of cancer caused by exposure to radioactive materials. It extends all the way to nuclear explosions and power plant accidents.
However, the word radiation simply refers to energy or particles that radiate from a source.
In the context of electromagnetic radiation (EMR), this covers everything from radio waves on the low end of the frequency to gamma rays on the highest end of the spectrum. Within this spectrum of radiation, we find things like X-rays, ultraviolet light, visible light, infrared light, microwaves, cellphones and radio waves (as in FM and AM bands).