Facebook is a social networking service launched in February 2004, owned and operated by Facebook, As of September 2012, Facebook has over one billion active users,more than half of whom use Facebook on a mobile device.Users must register before using the site, after which they may create a personal profile, add other users as friends, and exchange messages, including automatic notifications when they update their profile. Additionally, users may join common-interest user groups, organized by workplace, school or college, or other characteristics, and categorize their friends into lists such as "People From Work" or "Close Friends".
Facebook was founded by Mark Zuckerberg with his college roommates and fellow Harvard University students Eduardo Saverin, Andrew McCollum, Dustin Moskovitz and Chris Hughes. The website's membership was initially limited by the founders to Harvard students, but was expanded to other colleges in the Boston area, the Ivy League, and Stanford University
The name of the service stems from the colloquial name for the book given to students at the start of the academic year by some university administrations in the United States to help students get to know each other.
Born on May 14, 1984 in Dobbs Ferry, New York, Mark Zuckerberg co-founded the social-networking website Facebook out of his college dorm room. He left Harvard after his sophomore year to concentrate on the site, the user base of which has grown to more than 250 million people, making Zuckerberg a billionaire. The birth of Facebook was recently portrayed in the film The Social Network.