Facebook is the world’s largest social network, with over 500 million users. Facebook is a social networking service and website launched in February 2004, operated and privately owned by Facebook, Inc. Users may create a personal profile, add other users as friends, and exchange messages, including automatic notifications when they update their profile. Facebook users must register before using the site. Additionally, users may join common-interest user groups, organized by workplace, school or college, or other characteristics.
About (from The Facebook at www.facebook.com)
“Millions of people use Facebook everyday to keep up with friends, upload an unlimited number of photos, share links and videos, and learn more about the people they meet. Facebook's mission is to give people the power to share and make the world more”