Facebook is a Web site of setting in social network which makes it possible to people to communicate with their friends and to exchange information. Launched on February 4, 2004, Facebook was created by Mark Zuckerberg, a former student of Harvard of promotion 2006. The name of the site refers to the albums introducing the pupils that the American universities and preparatory schools give to the new students, the teachers and the personnel in order to better know the other people present on the campus. Initially, the only members of this group were students of the university of Harvard. The site was then opened at other universities of the area of Boston, then with the whole of the American universities most prestigious at the end of two months. Many other universities adhered to this network very quickly during the following year. Finally, all people having an address e-mail in a university (for example, an address carrying the edu suffix, ac.uk, etc.) where that it is located in the world could join this network. Other networks were then created for the colleges and certain large companies. Since September 11, 2006, the site is accessible to all the users, whatever their address e-mail, provided that they are located in a certain age bracket.
The users can choose to join one or more participating networks, such as a college, a place of work or a geographical area. In October 2007, this Web site counted the greatest number of users recorded among all the sites directed towards the university, with more than 42 million active members throughout the world, and it should cross the bar of the 60 million users by the end of the year (by also counting the nonuniversity networks). From September 2006 to September 2007, its classification among the Web sites more visited in the world passed from the 60th in the 7th place and it became the site number one for the division of the photographs in the United States, in front of sites such as Flickr and Photobucket, with more than 8,5 million photographs charged each day. Recently, the site profited from an investment of the giant of the software, Microsoft, which confers on Facebook a value of 15 billion dollars.