Google Search was originally called BackRub when Larry Page and Sergey Brin developed it at Stanford University.
The name referred to the system’s analysis of the web’s “back links,” or links pointing to a page. Page and Brin’s research focused on using those links to estimate the importance of web pages, an approach that became closely associated with PageRank.
BackRub operated on Stanford’s servers during 1996 and 1997. The project was later renamed Google, a play on “googol,” the mathematical term for the number 1 followed by 100 zeroes. Google’s founders registered the Google.com domain in September 1997.
BackRub is sometimes confused with PageRank, but they were not the same thing: BackRub was the search project’s early name, while PageRank was the ranking method developed for it. The company Google Inc. was incorporated in 1998.