Okay kiddo, do you know what radiation is? It's a type of energy that comes from things like the sun, and also some man-made things like X-ray machines. Sometimes, if people are around too much radiation, it can be harmful to their health.
So, back in 1960, some very smart grown-ups got together and decided to make a special set of rules to help protect people from harmful radiation. They called this set of rules the "radiation protection convention."
These rules said things like how much radiation is okay for people to be around, how to measure radiation, and how to keep people safe from radiation.
Everyone from different countries agreed to follow these rules, so that people all around the world could be kept safe from harmful radiation. And that's why we have the radiation protection convention, a way to help us all stay healthy!