NedreN said:I believe things like that are done with MySQL (Or another) database classes. Each query is counted, and the time it takes to complete and return is counted. Also the PHP scripts execution time is counted. At the end is does the math and ends up with the number you see on w/e page.
If you don't know OOP, I'm not sure how else to explain it to you. There are (I'm sure) other ways of getting it done. the way I described I would think would be one of the more common ways.