The term "Web 2.0" refers to what some people see as a second phase of development of the World Wide Web, including its architecture and its applications. As used by its proponents, the phrase refers to one or more of the following:

However, a consensus on its exact meaning has not yet been reached.

Many recently developed concepts and technologies are seen as contributing to Web 2.0, including weblogs, linklogs, podcasts, RSS feeds and other forms of many to many publishing; social software, web APIs, web standards, online web services, Ajax, and others.

Proponents of the Web 2.0 concept say that it differs from early web development, retroactively labeled Web 1.0, in that it is a move away from static websites, the use of search engines, and surfing from one website to the next, to a more dynamic and interactive World Wide Web. Others argue that, while "Web 2.0" may add some useful functionality to the existing framework, the original, fundamental building blocks of the WWW can never truly be superseded. Skeptics argue that the term is a buzzword, or that it means whatever its proponents decide that they want it to mean in order to convince the media and investors that they are creating something fundamentally new, rather than continuing to develop and use well-established technologies