Yahoo Inc. (stylized Yahoo!) is an American multinational Internet corporation headquartered in Sunnyvale, California. It is globally known for its Web portal, search engine Yahoo Search, and related services, including Yahoo Directory, Yahoo Mail,Yahoo News, Yahoo Finance, Yahoo Groups, Yahoo Answers, advertising, online mapping, video sharing, fantasy sports and its social media website. It is one of the most popular sites in the United States.^[8] According to news sources, roughly 700 million people visit Yahoo websites every month.^[9][10] Yahoo itself claims it attracts "more than half a billion consumers every month in more than 30 languages."^[11]

Yahoo was founded by Jerry Yang and David Filo in January 1994 and was incorporated on March 1, 1995. Marissa Mayer, a former Google executive, serves as CEO and President of the company.^[12]

According to comScore, Yahoo during July 2013 surpassed Google on the number of United States visitors to its websites for the first time since May 2011, set at 196 million United States visitors, having increased by 21 percent in a year.^[13]