ELI5: Explain Like I'm 5

Datum reference

Okay, sweetie. Imagine you want to build a very fancy Lego castle, but you want to make sure it's perfect. That's where datum reference comes in!

Basically, you need to pick a starting point, a place where all the other Lego pieces will be measured from. This starting point is called the datum reference.

Let's say you choose the bottom corner of your Lego baseplate as your datum reference. Now, every other piece you add to your castle will be measured from that corner. You might measure how far away other pieces are from that corner or what angles they are at compared to it.

By using a datum reference, you can make sure all the pieces of your castle fit together perfectly and exactly how you want them to.

In real life, people use datum references for all sorts of things, like making sure car parts fit together or measuring the exact location of buildings. It's like picking a starting point and making sure everything else lines up from there. Cool, huh?