Web 2.0 is a term often applied to a perceived on-going transition of the World Wide Web from a collection of web sites to a full-fledged computing platform serving web applications to end users. Ultimately Web 2.0 services are expected to replace desktop computing applications for many purposes.

It also refers to a perceived second generation of web-based communities and hosted services - such as social-networking sites, wikis and folksonomies - which facilitate collaboration and sharing between users.

Although the term suggests a new version of the World Wide Web, it does not refer to an update to Web technical specifications, but to changes in the ways software developers and end-users use the web as a platform. Web 2.0 is the business revolution in the computer industry caused by the move to the internet as platform, and an attempt to understand the rules for success on that new platform.

Some technology experts have questioned whether one can use the term in a meaningful way, since many of the technology components of “Web 2.0″ have existed since the early days of the Web.

In alluding to the “2.0″ version-numbers (in the term “Web 2.0″) that commonly designate software upgrades, the phrase may hint at an improved form of the World Wide Web.

Advocates of the concept suggest that the technologies such as weblogs, social bookmarking, wikis, podcasts, RSS feeds (and other forms of many-to-many publishing), social software, Web APIs, Web standards and online Web services imply a significant change in web usage. In other words, genuine interactivity if you like, simply because people can upload as well as download.

As used by its supporters, the phrase “Web 2.0″ can also refer to one or more of the following:

• the transition of web-sites from isolated information silos to sources of content and functionality, thus becoming computing platforms serving web applications to end-users
• a social phenomenon embracing an approach to generating and distributing Web content itself, characterized by open communication, decentralization of authority, freedom to share and re-use, and “the market as a conversation”
• a pronounced distinction between functionality and web technology, enabling significantly easier creation of new business models and processes by using readily available intuitive modular elements
• enhanced organization and categorization of content, emphasizing deep linking
• a rise in the economic value of the Web, possibly surpassing the impact of the dot-com boom of the late 1990s

During the first Web 2.0 conference, the key principles of Web 2.0 applications have been identified as follows:

• the web as a platform
• data as the driving force
• network effects created by an architecture of participation
• innovation in assembly of systems and sites composed by pulling together features from distributed, independent developers (a kind of “open source” development)
• lightweight business models enabled by content and service syndication
• the end of the software adoption cycle (”the perpetual beta”)
• software above the level of a single device, leveraging the power of the “Long Tail”
• ease of picking-up by early adopters

If you like to read more about Web 2.0, you can visit http://en.wikipedia.org/wiki/Web_2.0