Google ranks its search results using a proprietary page-ranking system that's partly based on how often a site is linked to from other sites.

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Sergey Brin and Larry Page originally developed link-based ranking for Google as Stanford grad students supported by an NSF fellowship.

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Or look at Google: Larry Page and Sergey Brin came up with their famous search algorithm by applying the ranking method used for academic articles (more citations equals more influence) to the sprawl of the Internet.

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