Everyone related to web development use a word which is very difficult to define. The word is WEB 2.0.
What is it ?
Web 2.0 is a trend in the use of www and webdesign that aims to enhance creativity, information sharing, and, most notably, collaboration among users.
Web 2.0 is a marketing buzzword, which is made up of a group of buzzwords.
Let me try to define the buzzwords which combine and make WEB 2.0.
The most important component of web 2.0 is RIA ie Rich Internet Applications.
Now you might ask what do i mean by rich internet applications. RIA means web applications which have a rich user interface. All of us have used desktop applications in one form or the other.
Some of the JS toolkits and libraries which provide development of RIA are DOJO, Prototye.js, Windows.js, Scriptaculous.js, Effects.js etc.
SOA - Service Oriented Atchitecture
Web 2.0 thrives on pulling information from different distributed and independent sources. RSS , ATOM feeds, REST calls, consuming wxposed services by various companies etc became the source of information which is presented on Rich UI. Web 2.0 Apps consumes a lot of information from these sources.
Web 2.0 Applications promotes social networking and colloboration amongst users. A nice example of Web 2.0 is Pramati technologies product ShopprStream. It allows user to write reviews, comment on existing posts, telling people about what a user found interesting on net etc. The whole idea is to bring user in picture. Empowering user and make him feel that he is part and parcel of the game. Instead of just browsing websites now user can edit them. Social web is a big factor behind the success of web 2.0 among the users.
Finally summarizing all the discussion WEB 2.0 is combination of RIA , SOA , Social WEB.