Facebook is a popular free social networking website that allows registered users to create profiles, upload photos and video, send messages and keep in touch with friends, family and colleagues. The site, which is available in 37 different languages, includes public features such as:
Marketplace - allows members to post, read and respond to classified ads.
Groups - allows members who have common interests to find each other and interact.
Events - allows members to publicize an event, invite guests and track who plans to attend.
Pages - allows members to create and promote a public page built around a specific topic.
Presence technology - allows members to see which contacts are online and chat.
Within each member's personal profile, there are several key networking components. The most popular is arguably the Wall, which is essentially a virtual bulletin board. Messages left on a member's Wall can be text, video or photos. Another popular component is the virtual Photo Album. Photos can be uploaded from the desktop or directly from a smartphonecamera. There is no limitation on quantity, but Facebook staff will remove inappropriate or copyrighted images. An interactive album feature allows the member's contacts (who are called generically called "friends") to comment on each other's photos and identify (tag) people in the photos. Another popular profile component is status updates, a microbloggingfeature that allows members to broadcast short Twitter-like announcements to their friends. All interactions are published in a news feed, which is distributed in real-time to the member's friends.
Facebook offers a range of privacy options to its members. A member can make all his communications visible to everyone, he can block specific connections or he can keep all his communications private. Members can choose whether or not to be searchable, decide which parts of their profile are public, decide what not to put in their news feed and determine exactly who can see their posts. For those members who wish to use Facebook to communicate privately, there is a message feature, which closely resembles email.
In May 2007, Facebook opened up its developers' platform to allow third-party developers to build applications and widgets that, once approved, could be distributed through the Facebook community. In May 2008, Facebook engineers announced Facebook Connect, a cross-site initiative that allows users to publish interactions on third-party partner sites in their Facebook news feed