Page Rank is a family of algorithms for assigning numerical weightings to hyperlinked documents indexed by a search engine. The Page Rank system is used by the popular search engine Google to help determine a page’s importance. It was developed by Google's founders Larry Page and Sergey Brin while at Stanford University in 1998. It is an algorithm used to rank websites in their search engine results. It relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. Page Rank is a quality metric such that the values 0 to 10 determine a page's importance, reliability and authority on the web according to Google.