ISO 6709 is a way of saying where you are in the world using numbers.
Imagine you are playing hide and seek with your friends, and you want to tell them where you are hiding. You can say "I am behind the big tree next to the playground." But sometimes it's hard to know which tree or where the playground is!
ISO 6709 is like a secret code that helps you tell someone exactly where you are. Instead of saying "I'm behind the big tree," you can use numbers to say something like "I am at 50.123 degrees North, and 1.234 degrees West."
This helps because the numbers are like an exact map, and your friends can use them to find you much more easily.
ISO 6709 is used for lots of things, not just hide and seek. It's commonly used in navigation or when tracking things like airplanes or ships. The numbers help people know exactly where things are in the world, even if they can't see them in person.