The company that became Google was originally called BackRub.
Larry Page and Sergey Brin began developing the search engine while they were doctoral students at Stanford University. The project was known as BackRub because its early ranking system analyzed the web's backlinks. Their work treated links as signals of importance, helping distinguish it from search systems that relied mainly on text matching.
The founders registered the google.com domain in September 1997 and incorporated Google, Inc. on September 4, 1998. The name Google was a play on googol, the mathematical term for the number 10 followed by 100 zeros. It suggested the enormous amount of information the search engine aimed to organize.
Google later became the central company of Alphabet Inc., created in 2015 as a corporate restructuring. BackRub is therefore the historical project name, not the name of Google's ranking algorithm or its parent company.