Radiation is a word that makes people very nervous. But, to radiate just means, giving off. Like when the radiator in your house gives off heat in the form of infrared radiation. Different parts of the electromagnetic spectrum correspond to different types of radiation. And, many of them are perfectly harmless. Some of them can be dangerous though. Radiation with very short wavelengths like UV Light, X-Rays, and Gamma Rays are strong enough to rip electrons out of their atoms, which can cause burns and genetic damage. This is what many people have in mind when they hear the term "radiation". The rest of the spectrum covers a large range of longer waves from Visible Light, Infrared, Microwaves to Radio Waves. This is the kind of radiation that's emitted by all sorts of human technology: mobile phones, Wi-Fi routers, electric power lines, and household appliances. This radiation doesn't disrupt molecules in our body. However, some kinds of radiation can stimulate muscles and nerves and can also make the hair on your body vibrate, which can sometimes cause a tingly feeling above certain threshold values, other kinds are useful for making dinner. Microwaves push the water molecules in your food around which warms it up. This happens to us all the time. For example, the pleasant warmth you feel at the beach is your skin heating up from exposure to electromagnetic infrared radiation from the sun. We are surrounded by natural, and generally harmless sources of electromagnetic radiation all the time and always have been.