Facebook

Facebook is a social networking service and website started in February 2004. It is owned by Facebook, Inc.

As of September 2012, Facebook has over one billion active users.
Users may make a personal profile, add other users as friends, and send messages.
The name of the service comes from the name of the book given to students at the start of the school year by some universities in the United States. These books help students get to know each other better.

• Facebook allows any users who say they are at least 13 years old to become users of the website.

Facebook was started by Mark Zuckerberg with his college roommates. 

The website's membership was only for Harvard students at first. Later it included other colleges in the Boston area, the Ivy League, and Stanford University.