Facebook

Facebook is a social networking service launched in February 2004.
It is owned and operated by Facebook, Inc.
As of September 2012, Facebook has over one billion active users,more than half of them using Facebook on a mobile device.
Facebook was founded by Mark Zuckerberg with his college roommates and fellow 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. It gradually added support for students at various other universities before opening to high school students, and eventually to anyone aged 13 and over.
A January 2009 Compete.com study ranked Facebook as the most used social networking service by worldwide monthly active users.In September 2012, Zuckerberg speaking about the drop in his company's market value, described the decline as "disappointing" - the value of Facebook being almost half the $38 debut price in May 2012.

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. Facebook allows any users who declare themselves to be at least 13 years old to become registered users of the site.
Zuckerberg was born in 1984 in White Plains, New York