Web 2.0/3.0 is also referred to as a network of weblogs that write content about the new generation of web. Some of the basic characteristics of web 2.0 are that it is rich, user friendly interface based on Ajax. Web 2.0 features a number of techniques. The most important and prominent feature of web 2.0 is the rich internet application techniques. It has a meaningful URL through which, you can extract the desired information.
Web 2.0 does not have a hard boundary. One could see it, as a set of principles that combine a veritable gambit of sites, which demonstrate some or all of those principles.
Web 3.0 has a rich user internet application. It has been figured out that internet application can improve the user experience in browser based application.
Web 2.0 allows a web page to update some or most part of its content. And, it is not required to refresh the whole page at that point.