Ordnance Survey is like a super mega map that shows you everything about a place. It is a very special kind of map that is used by people who want to know all about the land, the buildings, the roads, the rivers, the mountains, and everything in between in a specific area.
They have people who sneak around with special mapping equipment and take pictures and measurements of absolutely everything in the area. All these pictures and measurements are put together in a super large and complicated puzzle to make the final map. It is like a big game of connect the dots!
This map is very important because it helps people find their way around, plan where to build new buildings, and even helps with things like emergency services such as fires or floods.
And because Ordnance Survey is so good at making maps, people from all over the world use their maps to help them understand what is going on in different parts of our amazing planet.