Well kiddo, IEC 60309 is a set of standards that helps make sure that electrical devices and equipment can work safely with each other. It's kind of like when your parents tell you to look both ways before crossing the street – it's a way to make sure you don't get hurt.
IEC 60309 helps people who make all kinds of electrical stuff, like electrical plugs and sockets, make sure that everything fits together properly and safely. This is important because if something doesn't fit together properly, it can cause sparks or even start a fire. Nobody wants that, right?
IEC 60309 also makes sure that everything is labeled so people know exactly what kind of outlet or plug they're working with. This helps electricians and other people who work with electricity stay safe, too.
So, in a nutshell, IEC 60309 is a set of rules that helps make sure everything electrical is safe and works together properly so nobody gets hurt.