Google PageRank
In 1990s one algorithm was invented by Larry Page and Sergey Brin that is PageRank. PageRank is an Google patent that take care of the popularity of a particular page, link equity as a ranking factor is implemented by PageRank concept.
Votes are the incoming links to that page, indicating importance.
A page that is arrived at more often is likely more important and has a higher PageRank, when a page with higher PageRank link to another page will increase the rank of that page more on that basis. You can also read about the PageRank at Http://en.wikipedia.org/wiki/PageRank
Install the Google toolbar and enable PageRank feature or install searchstatus Plugin for Firefox. One most important thing is that the PageRank indicated by Google is a cached value, and is usually out of date. PageRank is updated only a few times per year, and sometimes using outdated information. Therefore PageRank is not a terribly accurate metric.
Google use its PageRank just as one factor in the collective algorithm when building search results pages (SERP’s). it is very much possible that a page with a lower PageRank above one with higher PageRank for a particular query. PageRank measures overall popularity using links, and not the subject shrouding them. Google these days investigating the relevancy of links when calculating search ranking, therefore PageRank is note the sole focus of a search engine marketer. Building relevant links will naturally contribute. To a higher PageRank. But, building too many irrelevant links solely for the purpose of increasing PageRank may actually hurt the ranking of the site, because Google attempts to detect and devalue irrelevant links that are presumably used to manipulate it.
PageRank is also widely regard by users as a trust-building factor. Indeed, this is what PageRank is designed to indicate. This perception is encouraged by the fact that Google penalize Spam are irrelevant site (or pages) by reducing or zeroing their PageRank.
