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

The first question can be answered by reading up on resources

Since you are SELECTing "*", every column is returned for each mysql_fetch_object call. Just look at print_r($row) to see.