Social networking sites help people get connected with others by sharing their interests, building online profiles, and sharing photos, videos, and music. Sociologists have been studying the idea of social networks for decades. They analyse the bonds between people in families, organisations, towns and countries. Early internet applications, like bulletin board systems and Usenet, enabled people to communicate and create networks.

Within a Web site, there are blogs, groups, dating, and forums. However, the basic unit is the individual page, such as MySpace, Facebook, Friendster, Orkut, Zude!, and Gather. These are like communities where you can share the things that are important to you or most interest you. If you are into a certain hobby, social networking sites available to you include Fatsecret, a site for diet solutions; Fuzzter.com, a social network for your pets; BakeSpace.com, a site for cooks and bakers; Infield Parking, a site for race fans; Common Circle; WetCanvas!; and Vinorati.

In 2000, Friendster turned out to be the leader of social networking sites. This site features a list of friends or contacts maintained by each user or member. In 2003, MySpace was launched by Tom Anderson. This site lets people customise their pages, share videos with other friends, and upload music. In 2004, a new social networking site called Facebook arrived, a rival of MySpace. Facebook is a site that lets people make widgets or mini applications for the site. This community went from 8.9 million registered users in September 2006 to more than 37 million users now.