what is the difference between radiation and electromagnetic radiation?
Electromagnetic radiation is the consequence of this - the fields move with the speed of light and 'radiate' from a source. I'm not sure what you mean by 'Like what type of radiation are they talking about'. Anything that is radiated, that emanates from an object, is radiation. It's nothing to do with radioactivity - well, gamma is a specific type of electromagneitc radiation, but alpha and beta are not. The electromagnetic spectrum is the combination of all types of electromagnetic radiation. We artificially divide the spectrum up into categories based on the effects of the radiation and the causes of the radiation, but in essence there's not much difference between a low-frequency radio wave and a high-frequency gamma ray, apart from the frequency.