PageRank was once at the very core of search – and was what made Google the empire it is today. Even if you believe that search has moved on from PageRank, there’s no denying that it has long been a pervasive concept in the industry. Every SEO pro should have a good grasp of what PageRank was – and what it still is today. Created by Google founders Larry Page and Sergey Brin, PageRank is an algorithm based on the combined relative strengths of all the hyperlinks on the Internet. Most people argue that the name was based on Larry Page’s surname, whilst others suggest “Page” refers to a web page. Both positions are likely true, and the overlap was probably intentional. The paper went on to become a patent in the U.S. (but not in Europe, where mathematical formulas are not patentable). Stanford University owns the patent and has assigned it to Google. The patent is currently due to expire in 2027.