Ordnance Datum

Ordnance datum is like a special line that we use to measure heights of things.

Imagine you are playing with blocks and you want to build a tower as tall as you can. If you don't have a way to measure how tall your tower is, you won't know if it's taller than your friend's tower.

So, if you use ordnance datum, you can measure the height of your tower in comparison to the height of the ground. It's like a starting point to measure heights from.

Think of ordnance datum as the zero line on a ruler. The ruler helps you measure the length of different things, and the zero line is where you start measuring from. Ordnance datum is like the zero line, but for measuring heights instead of lengths.

Using ordnance datum is important because it helps make sure that we are all measuring heights the same way, so everyone knows exactly how tall things are. It also helps us create accurate maps and plans for buildings and structures, which is really helpful for lots of different things.