You might hear the word radiation and think that it's a bad thing. It's true that there are certain types of radiation that are bad for you, but other types of radiation are important parts of your life. When you feel heat from the sun, see all the colors around you, or listen to the radio, you are actually experiencing different types of radiation.
These types of radiation are all part of the electromagnetic spectrum, which means they involve energy traveling in the form of a wave. Different types of radiation have different wavelengths.