Claim: Mark Zuckerberg and his four roommates co-founded a website.

Facebook is an American for-profit corporation and an online social media and social networking service based in Menlo Park , California . The Facebook website was launched on February 4 , 2004 , by Mark Zuckerberg , along with fellow Harvard College students and roommates , Eduardo Saverin , Andrew McCollum , Dustin Moskovitz , and Chris Hughes .   The founders had initially limited the website 's membership to Harvard students ; however , later they expanded it to higher education institutions in the Boston area , the Ivy League schools , and Stanford University . Facebook gradually added support for students at various other universities , and eventually to high school students as well . Since 2006 , anyone age 13 and older has been allowed to become a registered user of Facebook , though variations exist in the minimum age requirement , depending on applicable local laws . The Facebook name comes from the face book directories often given to United States university students .   Facebook may be accessed by a large range of desktops , laptops , tablet computers , and smartphones over the Internet and mobile networks . After registering to use the site , users can create a user profile indicating their name , occupation , schools attended and so on . Users can add other users as `` friends '' , exchange messages , post status updates and digital photos , share digital videos and links , use various software applications -LRB- `` apps '' -RRB- , and receive notifications when others update their profiles or make posts . Additionally , users may join common-interest user groups organized by workplace , school , hobbies or other topics , and categorize their friends into lists such as `` People From Work '' or `` Close Friends '' . In groups , editors can pin posts to top . Additionally , users can complain about or block unpleasant people . Because of the large volume of data that users submit to the service , Facebook has come under scrutiny for its privacy policies . Facebook makes most of its revenue from advertisements which appear onscreen .   Facebook , Inc. held its initial public offering -LRB- IPO -RRB- in February 2012 , and began selling stock to the public three months later , reaching an original peak market capitalization of $ 104 billion . On July 13 , 2015 , Facebook became the fastest company in the Standard & Poor 's 500 Index to reach a market cap of $ 250 billion . Facebook has more than 1.94 billion monthly active users as of March 31 , 2017 . As of April 2016 , Facebook was the most popular social networking site in the world , based on the number of active user accounts . Facebook classifies users from the ages of 13 to 18 as minors and therefore sets their profiles to share content with friends only .