"One of the major breakthroughs with Google’s search engine was a formula called PageRank, named after Larry Page, one of Google’s founders and now the chief executive of its parent company, Alphabet. PageRank works on the basic premise that a page’s value can be determined by how many sites link to it. In the early days of web search, this was a novel concept, and it helped to propel Google past competitors like Yahoo and AltaVista. The search engine has gotten more sophisticated over the years. (It was founded 20 years ago on Tuesday.) In addition to PageRank, the company has also said that the software looks at how often and where the keywords being searched for show up on a specific page, how recently the page was created (a sign of the freshness of the information) and the location of the person making the search."