Page rank is Google’s method of ranking a page. It is a numeric value out of 10 that signifies how important a page is on the web. Page rank is a very important aspect that every expert of search engine optimization takes into account. Generally page rank is calculated depending upon the number of inbound links that a page has, including various other factors. The PR of a page is displayed on the page rank bar if Google toolbar is installed in the site.

Google describes Page Rank thus:

Page Rank 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.”

Page rank was invented by Larry Page, the founder of Google, and it is the basis of Google’s function. Google considers the links to be votes to a page and it calculates all the link votes along with some other features of the page to determine the page rank. A site gets links if it has got some relevant reason to do so. For the web browsers page rank is the scale to find out the validity and accuracy of the page.

Page rank is the main object of consideration for the SEO experts. A link from another page increases the page rank of the linked page. If the page giving link has a good page rank, the link value increases. Hence, when link popularity becomes the prime factor to improve the page rank of a page, quality links matters more for Google.

It is difficult to understand how Google calculates the page rank, but it is analyzed as one of the many factors to determine the position of a page in SERPs. However, page rank can be manipulated by getting links from sites with higher PR. SEO experts concentrate more on the aspect of page rank and work out on the strategies to be in the competition.

Google keeps on changing the PR of a page by indexing and re-indexing it. It combines the page rank of a page with text matching methods to select the web pages on the SERPs that are relevant and significant for the visitors according to their search terms.