What type of radiation are radio signals?

In physics, the term "radiation" simply refers to energy traveling through space. Radio signals are a form of electromagnetic radiation, but they are specifically classified as non-ionizing radiation. This means they do not carry enough energy to strip electrons from atoms or molecules. Because radio waves cannot ionize atoms, they do not cause the type of genetic or cellular damage associated with radioactivity. Their primary biological effect at high power levels is simply tissue heating, much like how a microwave oven warms up food. Options like gamma, alpha, or "ionizing" radiation are incorrect because they describe highly energetic radiation (like from nuclear decay or X-rays) that can alter DNA and cause radiation sickness. Radio waves sit safely at the low-energy end of the electromagnetic spectrum.