Schematron

Schematron is like a set of rules that helps you check if something is done right. Imagine you have a big puzzle that you need to put together. Schematron is like a list of directions that tells you how to put the puzzle together, and it checks if you did it correctly.

Say you have a website and you want to make sure that every page has a title. Schematron would check all your pages to make sure they have a title, and if they don't, it would say, "Hey, you forgot to put a title on this page!" It would also tell you where you made the mistake, so you can fix it.

Schematron is really useful because it can check lots of things all at once, and it can be customized to check for different things depending on what you need. It's like a puzzle solver and a detective all rolled into one!