The Pagerank is the search engine Google used methods for evaluating the link popularity. Google Pagerank 1997, led the ranking with search engines and read him the tiling. The pager rank is expressed in a number between 1 and 10 from 10 being the highest value is that for the search engine ranking can reach a site. Achieve a Pagerank of 10, very few sites.

To evaluate a site for the search engine ranking in Google Pagerank is the basis of the number and quality of incoming links to a document valued at. And the quality of incoming links is used increasingly for the calculation of Pagerank as the number of incoming links can be manipulated by webmasters to easily.

The more quality links a document receives the higher is the Pagerank for this document. The higher the value of PageRank, the better it is for the ranking of a document in the search results. Of course, a high Pagerank is no guarantee to book the best positions, because ultimately many other criteria with a flow that have influence on the ranking.

Google evaluates incoming links a document receives, so to speak as a “recommendation” and ranked it accordingly in computing the Pagerank for the search engine ranking. Furthermore, Google also evaluates the links to a document emanating from. Thus, your own documents Pagerank form of a link to another document to pass in (pass on). If a document, however, two or more outgoing links, the value of the share can document the number of outbound links divided Sun A document its full Pagerank never pass. For example, a site with PageRank 5 is only a PageRank of less than 5 always pass on to other documents. Basically, the page will always the highest PageRank, the most incoming links from sites with high Pagerank also replaced as well. In calculating the PageRank value for the search engine ranking, external links (ie the other of a domain are also links) are included and project internal links (links or coming from the same domain are stored the under as the document for which the Pagerank is computed even).

Example:

The site A as in the form of a link to the site, As a result, Google is expected that the site receives B from the site A is a “recommendation” and writes a value B increases from B to which the Pagerank.

B could pass on its Pagerank now by placing a link to another website. Set B to two or more websites to link, then the PageRank, which is inherited, is divided accordingly. Adopted to calculate the Pagerank for B shows that B can pass on a value of 3.

If B is now on two other documents (C and D) a link, these documents will each have a value of 1.5 for their own Pagerank sum up (because the value can pass on the B (ie 3) to all outgoing links from B equal divided, is thus replaced by B and C respectively 1.5).

From this we can derive a rule for the web site optimization:
You should always try to get links from sites that already have a high Pagerank. The higher the PageRank of a page, the higher the value of the this page can pass.

The original algorithm for computing the Pagerank for the search engine ranking on Google:

PR (A) = (1-d) + d (PR (T1) / C (T1) + … + PR (Tn) / C (TN))

Explanation:

PR (A): Pagerank of the document A
PR (T1): Pagerank of the document which T1 link to the document A
d: damping factor, the value is between 0 and 1 (mostly amounts to 0.85)
C (T1): the total number of outbound links from the document T1
PR (Tn) / C (TN): This part of the equation indicates that for every document linked to the (A), a Pagerank value is calculated.

Since all Pageranks between linked sites are more or less dependent, the calculation of Pagerank for all documents so frequently carried out in sequence given until an adequate approximation to an exact value is (iterative calculation).

Because some documents to start and have no PageRank value (eg if you were logged in the search engine of hand and no incoming links) have received all the documents assigned a start value which, for example from other methods for assessing the relevance can be determined.

The above equation for calculating the Pagerank is the purely original version of the Pagerank algorithm. It provides for all search engines more or less based on the relevance assessment by Link popularity is the (almost all search engines use a method similar to the Pagerank).

However, a calculation of PageRank is now in this form is no longer carried out to calculate the relevance to the search engine ranking. The algorithm shown above is from Google and other search engines constantly evolving and changing to accommodate the current situation (eg action against search engine spam) to adapt or improve the quality of search results. The current algorithms to calculate the Google Pagerank is a well-kept secret.

For this reason here is not to calculate the Pagerank discussed in depth as the original formula is no longer a method to determine the Pagerank and therefore less relevant to search engine optimization is. To this end, there are already enough web Information material which treats this subject well.