system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Radiation

Just what IS it? What does it do? What creates it?
gpt
Some atoms are not meant to be.  Like a house of cards, they will eventually fall apart.

When they do, little bits fall off.  Some of these little bits are matter, like neutrons, protons, and electrons.  Others are forms of light called gamma rays.  Collectively, they are called radiation.  They typically are shot out with a lot of energy, and can break down molecules in your body.