What is Page Rank? How to calculate the PR?

What is Page Rank? How to calculate the PR?

PageRank is a measure of the importance of pages, according to the search engine Google. PR depends on the number of external links on this page and on their quality (in turn the number of external links to related pages).The name rozshifrovuetsya as Page of the name of one of the founders of Google - Lari Page and Rank - rank.
Analog Witz (Weighted Citation index), Yandex.In fact, PageRank - Google is a method for measuring the "importance" page. When all other factors, such as Title tags and keywords are taken into account, Google uses PageRank, to adjust the results so that more "important" sites will rise accordingly up on a search results page a user.Page Rank is calculated by a special formula:PR (A) = (a-d) + d (PR (T1) / C (T1) + ... + PR (Tn) / C (Tn))It is possible that by now the formula has undergone several modifications, but Google in the press this was not mentioned. However, it does not matter, because it is the original equation quite well.In this equation - are pages linking to page A, - leaving out the number of options, and damping factor, which is usually set to 0.85.
You can write it in a simpler form:PageRank page A = 0.15 + 0.85 * (share PageRank of each page, which refers to our home page A) where the share is nothing like PageRank link to other pages, Page A divided by the number of outgoing links page.Page vote part of his PageRank for every page to which it refers. Share PageRank passed in the voting process, slightly less than its own PageRank of the page (ie - the value of its own PageRank * 0.85). This value is evenly divided between all the pages on which there are links from this page.