Google PageRank

The Google PageRank system is a link algorithm that assigns a ranking out of 10 to every hyperlinked page on the web. Google uses the number of inbound links to a page to determine it's relative importance within the World Wide Web. Google has trademarked the name PageRank and the process is patented by Stanford University. PageRank was developed by Larry Page while stdying at Stanford, beginning in 1995. Larry Page and Sergey Brin used this system to help create a prototype which they named Google in 1998. While PageRank is just one of a whole slew of factors that determine the Search Engine ranking of a particular page, it is used by all of Google's web search tools.

m0serious, the SEO rapper, has a rap about PageRank: