What really is Page Rank? How important it is?

PageRank, a link analysis algorithm used by Google search engine that assigns a numerical weighting to each element of a hyperlinked set of documents, such as the World Wide Web, with the purpose of "measuring" its relative importance within the set. The algorithm may be applied to any collection of entities with reciprocal quotations and references.

PageRank is Google's way of deciding a page's importance. It matters because it is one of the factors that determines a page's ranking in the search results. It isn't the only factor that Google uses to rank pages, but it is an important one.



From Google PageRank Technology:

• PageRank Technology: PageRank reflects our view of the importance of web pages by considering more than 500 million variables and 2 billion terms. Pages that we believe are important pages receive a higher PageRank and are more likely to appear at the top of the search results.

  PageRank also considers the importance of each page that casts a vote, as votes from some pages are considered to have greater value, thus giving the linked page greater value. We have always taken a pragmatic approach to help improve search quality and create useful products, and our technology uses the collective intelligence of the web to determine a page's importance.

Google Page Rank is a factor that Google assigns to web pages in its index. It is based on the number of links Google has found pointing to a certain web page. Links can be from other web sites as well as from other pages in the same site. The rank varies from 0 to 10. 0 means less (or zero) number of incoming links and 10 means the highest number of incoming links.





PR is just one factor that Google looks at when they determine your site/blog’s SERPs. (View the above video about ranking and listen to 0:53 - 0:54 of Matt Cutt's says page rank included as a ranking factor.)

Another importance of PR in determining SERPs is backlinks (or how many links from other sites (and even within your own sites) point to your domain. In fact backlinks seem to have a more direct impact upon traffic levels. Google considers a link from another page as a vote for quality and PR is difficult to abuse than other ranking factors. And also gaining a PR takes time and it illustrates the establishment of a web site which is a good factor to consider when ranking web sites.

Many SEOs are very obsessed with this PR since I have read about news that through this PR they can earn(buying and selling links) and Google detects it. (Google Caught Selling High PageRank Links, Again & Again). They are making business with this green thing. I've been seo for 2 years and the fact that many seo expert (as they tell us) on the forums, "saying that PR is worthless". For me as long as Google uses it has still value.