What is Web 2.0?

Simply web 2.0 is user-generated, people bascially control the internet and have power to change it.

"Web 2.0" refers to a perceived second generation of web development and design, that facilitates communication, secure information sharing, interoperability, and collaboration on the World Wide Web. Web 2.0 concepts have led to the development and evolution of web-based communities, hosted services, and applications; such as social-networking sites, video-sharing sites, wikis, blogs, and folksonomies.

The term Web 2.0 was first used in front of a large audience by Eric Knorr, executive editor of InfoWorld, in the December 2003 special issue of the business IT magazine CIO, with the title "Fast Forward 2010 - The Fate of IT", in his article "2004 - The Year of Web Services". Eric Knorr wrote about the coming business revolution in the IT industry:
“ [An increase of outsourcing with web services] is nothing less than the start of what Scott Dietzen, CTO of BEA Systems, calls the Web 2.0, where the Web becomes a universal, standards-based integration platform. Web 1.0 (HTTP, TCP/IP and HTML) is the core of enterprise infrastructure.[1] ”

Eric Knorr quoted in his article Scott Dietzen, who was at that time CTO at BEA Systems (a subsidiary of Oracle) and is as of today President and CTO[2] at Zimbra, Inc., a Web 2.0 company which was purchased by Yahoo! for approximately $350 million in September 2007[3]. The term was later also used by Dale Dougherty and Craig Cline and shortly after became notable after the O'Reilly Media Web 2.0 conference in 2004.[4][5] Although the term suggests a new version of the World Wide Web, it does not refer to an update to any technical specifications, but rather to cumulative changes in the ways software developers and end-users utilize the Web. According to Tim O'Reilly:
“ Web 2.0 is the business revolution in the computer industry caused by the move to the Internet as a platform, and an attempt to understand the rules for success on that new platform.[6]
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Lots of great videos on YouTube describing the evolution of 1.0, 2.0, and now 3.0. Visually, may be easier to comprehend.

Web 2.0 is a buzzword that exploded in popularity sometime in 2005. In 2004, software guru Tim O'Reilly founded the Web 2.0 Conference, held annually in San Francisco. It has since expanded from a conference into a way of thinking, a new approach to doing business on the Internet. There is no standard definition for web 2.0, as it is a cluster of ideas rather than anything clear-cut. However, O'Reilly's comments on the topic are seen as having special authority, and rank among the top Google search results for the term.

The first premise of web 2.0 is leveraging the power of the user. For example, fluid user tagging of content would be used instead of a centralized taxonomy. Web 2.0 entrepreneurs often consider the Long Tail, which is basically an observation that the vast majority of the attention market is based on niche content. Web 2.0 is radically decentralized, as in the case of BitTorrent, a collaborative downloading co-op that consumes a serious portion of all Internet traffic.

Blogs are considered web 2.0. Instead of centralized "personal home pages", blogs let people easily post as much or as little as they want as rarely or as frequently as they want. Feed aggregators ensure that people only need to visit a single site to see all the feeds they subscribe to. Comments are enabled everywhere, allowing people to participate rather than passively consume content.

The web page Digg is an example of web 2.0. Unlike traditional news pages for which editors choose the top stories, Digg's front page content is determined by the voting of many thousands of users. The more votes a story gets, the more likely it is to be featured on the front page.

Web 2.0 marketing is supposed to be viral - that is, happy users encouraging their friends to use a product, rather than massive advertising brainwashing people into doing so. This ties in with the idea of "permission marketing" - marketing that actually gets the permission of its targets rather than shoving an ad in someone's face against their will. Some people call web 2.0 just another bubble like the first. Only time will tell whether these companies are truly profitable or "merely" trendy and useful.