Google was founded in 1998 by Larry Page and Sergey Brin while they were PhD students at Stanford University. They developed a new search algorithm called PageRank that analyzed backlinks to determine a website's importance. Google grew rapidly and had over 1 billion monthly users by 2011. It had its IPO in 2004, raising $1.67 billion, and became a publicly traded company. Google has acquired many companies over the years, including YouTube in 2006, to expand its business and remains focused on organizing the world's information.