What is Pr?

I will not paint a whole page about What is PRI will write only what I think is necessary and sufficient to know about PR. Thus, PR he's PageRank or PR yavlyayutsya kind of rating Google search. Page Rank, as is evident from the title - is page rank. Google assigns each page a rank. PR helps Google decide on extradition. That is, if the particular request comes several completely identical in its relevant sites, but they in fact can not be put at one place, you need someone to put the above, someone below, here and apply another filter - comparing page ranka page. Here, in principle, and all for a start, you need to know about Pr.