is a social networking website that operated by Facebook, Inc. Facebook's users can add friends, send messages, and also update their personal profiles to notify friends about themselves. Facebook user's also can join networks or groups which organized by workplace, school, or friends. 
Facebook was created by Mark Zuckerberg with his college roomates and his computer students, Eduardo Saverin, Dustin Moskovitz, and also Chris Hughes. He founded facebook when he still attending in Harvard University. Until now facebook has more than 350 million active users worldwide. Facebook has met some controversies. It has been blocked in several countries like Syria, China, Vietnam, and Iran. It also been banned in several workplace.
Nowaday, facebook has been used in a lot smartphones. Many new smartphones offer acces to Facebook services through web browsers or application. The facebook iPhone application was launched on August 2007 and in July 2008, over 1.5 million people use it regularly.Nokia also offers Facebook application on its Ovi Store, Nokia S60 devices such as the N97, contains most of the functionality of full website. In the other hand, RIM (Blackberry) and Google's Android 2.0 OS automatically incudes and official Facebook app. The application has options to sync Facebook friends with contacts, which adds profile pictures and status updates to the contact list. This one reason that Facebook become the most users Social Network today.
