Preorder field

Okay, so imagine you're going to a store to buy some candy. You see a lot of candies on the shelves, but you don't want to spend all your money on just one type of candy. You want to make sure you buy all the candies you want before anyone else does.

Now imagine the store has a special way of organizing the candies to help you. Each candy has a number written on it, starting from 1 and going up to however many candies are on the shelf. This number is called the "preorder field."

This means that the candies with a lower preorder field number come first, and the candies with a higher preorder field number come later. So if you want a candy with a low preorder field number, you have to grab it quickly before someone else does.

The preorder field is used in many other situations too, not just for candies. It helps us organize things in a particular order, so we can easily find what we're looking for and make sure we get it before anyone else does.