John Battelle writes,It began with an argument. It was hardly love at first sight. The two clashed incessantly, debating, among other things, the value of various approaches to urban planning. At stanford, Page began searching for a topic for his doctoral thesis. It was an important decision. He kicked around 10 or so intriguing ideas, but found himself attracted to the burgeoning World Wide Web. Page noticed that while it was trivial to follow links from one page to another, it was nontrivial to discover links back. Tim Berners-Lee's desire to improve this system that led him to create the World Wide Web. And it was Larry Page and Sergey Brin's attempts to reverse engineer Berners-Lee's World Wide Web that led to Google. The needle that threads these efforts together is citation - the practice of pointing to other people's work in order to build up your own.
Page reasoned that the entire Web was loosely based on the premise of citation - after all, what is a link but a citation? If he could divine a method to count and qualify each backlink on the Web, as Page puts it "the Web would become a more valuable place." At the time the computing resources required to crawl such a beast were well beyond the usual bounds of a student project. Unaware of exactly what he was getting into, Page began building out his crawler. In March 1996, Page pointed his crawler at just one page - his homepage at Stanford - and let it loose. The crawler worked outward from there. Inspired by citation analysis, Page realized that a raw count of links to a page would be a useful guide to that page's rank. He also saw that each link needed its own ranking, based on the link count of its originating page. But such an approach creates a difficult and recursive mathematical challenge - you not only have to count a particular page's links, you also have to count the links attached to the links. The math gets complicated rather quickly.Together, Page and Brin created a ranking system that rewarded links that came from sources that were important and penalized those that did not. Page and Brin's breakthrough was to create an algorithm - dubbed PageRank after Page - that manages to take into account both the number of links into a particular site and the number of links into each of the linking sites.Not only was the engine good, but Page and Brin realized it would scale as the Web scaled. Because PageRank worked by analyzing links, the bigger the Web, the better the engine. That fact inspired the founders to name their new engine Google, after googol, the term for the numeral 1 followed by 100 zeroes. They released the first version of Google on the Stanford Web site in August 1996 - one year after they met.