In November of 1997 in the paper,”The Anatomy of a Large-Scale Hypertextual Web Search Engine,” Sergey Brin and Lawrence Page presented the first prototype of a large-scale search engine called Google. In this paper, Brin and Page elaborate on the three algorithms that would form the backbone of the world’s dominant search engine: PageRank, Anchor Text and Proximity. Anchor Text and Proximity contributed to making Google Search unique but it was PageRank that made it revolutionary. PageRank brought order to the web. It was able to democratize search.

“PageRank treats a link from web page A to web page B as a “vote” by page A in favor of page B. The PageRank of a page is the sum of the pages that link to it. The PageRank of a web page also depends on the importance (or PageRank) of the other web pages casting the votes. Votes cast by important web pages with high PageRank weigh more heavily and are more influential in deciding the PageRank of pages on the web.”

This idea of “voting” made search results more relevant. The results you got were not just advertisers but they were relevant to individual search. This idea made Google Search better than the search engines that existed then: Yahoo! Search, Ask Jeeves (now Ask.com), WebCrawler, Excite and HotBot.

But very soon (2017), the patent on PageRank will expire.

“The first version of the PageRank technology was created while Larry and Sergey attended Stanford University, which owns a patent to PageRank. The PageRank patent expires in 2017.” Google Inc.’s 10K for fiscal year ended December 31st, 2009.