What is Google PageRank?

Google PageRank is an algorithm for ranking websites by assigning them numerical values (from 0-10) based on various criteria. It was developed by Larry Page at Stanford University. Google uses it to help determine where a page should be placed in Google search results.

How does Google calculate PageRank?

Google's PageRank system is recursive in nature; that is, a single page's PageRank relies on the PageRank of other pages that link to it. The more pages of higher PageRank (PR) you have linking to your site, the higher your site's PageRank will be. Google describes PageRank like this:

"PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at more than the sheer volume of votes, or links a page receives; it also analyzes the page that casts the vote. Votes cast by pages that are themselves 'important' weigh more heavily and help to make other pages 'important.'"

In addition, the scale for PageRank is logarithmic; thus, it becomes increasingly harder to progress upwards through the ranks (i.e., the difference between a PR1 site and a PR2 site is much greater than the difference between PR7 site and a PR8 site).