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Web 2.0 is a very controversial name. Some claim that there is no version 2.0 of the web, it is essentially the same web as always with different uses, others claim that it is a new concept that defines the Web as a platform (like an operating system) in which services can be built and therefore it is a new version of the Web. According to O’Reilly , “the concept of “Web 2.0” began with a conference brainstorming session between O’Reilly and MediaLive International. It is a “second-generation of Internet-based services – such as social networking sites, Wikis, communication tools and folksonomies – that let people collaborate and share information online in previously unavailable ways.” Web 2.0 is a more dynamic and interactive World Wide Web [O’Reilly, 2005].
According to O’Reilly  “Web 2.0 is the era when people have come to realize that it's not the software that enables the web that matters so much as the services that are delivered over the web.” Web 2.0 is about social media, users provide content to the Internet and once it is posted it can be fed continuously by other users and new services can be created [Gomero, 2006]. The Web of documents is now a Web of data, we are no longer just looking to the same old sources for information [MacManus & MacManus and Porter, 2005].
Van Der Henst  on the other side suggests that the Web 2.0 is more about a transition in the use of traditional applications to those that are focused to the final user. These applications generate collaborations and new services that are now replacing desktop applications. Web 2.0 concept was formulated by example: comparing services existing in the traditional web to those that had been born later on and were considered to be Web 2.0 because of their social use.