Web 2.0 is a term which was coined at a series of conferences by O'Reilly Media in 2004. The phrase suggests that a second-generation of web communities have formed since the inception of the World Wide Web. Although the Web 2.0 utilizes the same technology as the World Wide Web, the mode in which programmers and users alike view the platform has changed. The biggest key of the Web 2.0 is the emphasis on sharing within an online community. Wikis (for example, Wikipedia), blogs, and social networking sites (for example, Facebook) are cornerstones of the new community based ideal of the Web 2.0. In summary, the Web 2.0 could be described as a "social phenomenon embracing an approach to generating and distributing Web content itself, characterized by open communication, decentralization of authority, and the freedom to share and re-use" .
-  http://en.wikipedia.org/wiki/Web_2.0 Accessed 2007-5-14.