How do PHP/MySQL database queries work exactly?

Question

I have used MySQL a lot, but I always wondered exactly how does it work - when I get a positive result, where is the data stored exactly? For example, I write like this:

Answer 1

In simple words the resource returned it like an ID that the MySQL library associate with other data. I think it is like the identification card in your wallet, it's just a number and some information but asociated with a lot of more information if you give it to the goverment, or your cell-phone company, etc.