How Google Calculate the Page Rank

There are many legends about something that has no a priori scientific definition, something like the recipe for Coca Cola. All we tasted their wisdom to make it, but nobody is able to reproduce accurately. But how and to what is calculated based on our Page Rank.

It would be unfair to say that the Page Rank is calculated as the square root of the sum of the two sides squared. Obviously we define to Google, as an algorithm, even team is behind, because despite the magic that some believe that Google is sometimes do manually, the company philosophy to make sense of the information of millions of websites, can not be a manual task. So if we think of google algorithms, we can, as in every computer, do a little reverse engineering. So it is very important to know how google calculate page rank.