IEC 60320 is a special set of rules (kind of like a big rulebook) that helps make electronic devices, like computers and appliances, safe to use. It's like a grown-up's way of making sure that the things we plug into the wall won't give us a shock or burn us if something goes wrong.
IEC 60320 has different rules for different devices. For example, if you have a computer, it might have a special plug called a C13. This plug fits into a special outlet on the back of your computer that's designed to keep it safe. The rules say how big the plug should be, how it should be shaped, and how it should connect to the outlet.
If you have a toaster or a coffee maker, it might have a different plug called a C15. This plug is designed to work with devices that are a little bit hotter than computers. It's still safe, though, because IEC 60320 makes sure that the plug is designed to handle the heat without getting too hot itself.
So, basically, IEC 60320 is a set of rules that helps keep us safe when we use electronic devices. It tells device makers how to make their plugs and outlets so that they won't hurt us, even if something goes wrong.