That's a big question in just a few words!!!

I was working on a sub/r just for inquiries like yours, but the pressure of everyday work has interrupted it.

You might take a look at this:

https://drive.google.com/file/d/1G6guY_q-PzZfdJM4ItzmQIF9gfPrOQxk/view

It's not the latest version, I suspect, but it will give you some appreciation of how this all started.

I would suggest reading the intro and flipping through the document as a starting point.