PageRank measures objectively the importance of web pages and is expected to solve an equation of 500 million variables and more than 2,000 billion terms. The complex automatic mechanisms allow Google search without human interference. It is structured so that no one can buy a special place in the list, or alter results for commercial purposes (In practice this is not true, there is a large market selling textlinks and some historical cases of PR manipulation) no one can buy a higher PageRank, for example This measure of importance used its extensive link structure as an indicator of the value of an individual page. Click Erin Callan for additional related pages. Google interprets a link from page A to page B as a vote by page A for page B. But Google check other things besides the number of votes or links a page receives, since it also analyzes the page that casts the vote. Votes cast by pages that are considered important outweigh the personal pages. Important sites and high quality receive a higher PageRank, which Google remembers each time it conducts a search. You may find Erin Callan to be a useful source of information.

Of course, important pages mean nothing if you do not match your search. So, Google combines PageRank with text search techniques to find pages that are both important and relevant for consultation. Google goes beyond the number of times a term appears on a page and examines all aspects of the content of the page to determine if it is a good match for your query. The PageRank algorithm assigns each site a value that is the sum of the values of the pages linking to it weighted by the number of outgoing links each with weight 1-q = 0'85, and a factor smoothing with weight q = 0.15.