Facebook is an online social networking service. Its name comes from a colloquialism for the directory given to American university students. Facebook was founded in February 2004 by Mark Zuckerberg with his college roommates and fellow Harvard University students Eduardo Saverin,Andrew McCollum, Dustin Moskovitz and Chris Hughes. Users must register before using the site, after which they may create a personal profile, add other users as friends, exchange messages, and receive 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" As of September 2012, Facebook has over one billion active users ,of which 8.7% are fake. Facebook (as of 2012) has about 180 petabytes of data per year and grows by over half a petabyte every 24 hours. In May 2005, Accel partners invested $12.7 million in Facebook; on its 2012 income of US$5.1 billion; in May 2013, being placed at position 462.
Users can create profiles with photos, lists of personal interests, contact information, and other personal information. Users can communicate with friends and other users through private or public messages and a chat feature. They can also create and join interest groups and "like pages" (called "fan pages" until April 19, 2010), some of which are maintained by organizations as a means of advertising
