Yesterday , one of my friend called me and asked me about Web 2.0 and he wants a ppt based on it .He have to take a seminar in his office . "Web 2.0" , the change came exponentially.Till recently I thought it didnt have much to help us,but the truth itself got revealed.Now it seems to have acquired enough meaning as it changed the thought , "its of no use for us". I first heard "web2.0" from my friends who were discussing about new technologies.When I went through the O'Reilly website,I really figured out the

definition of web2.0.
Tim O'Reilly says the phrase "web2.0" actually came out from the brainstorming session between O'Reilly and Medialive International.They want the web to be more important than ever,with exciting applications and sites popping out with regularity.

As per O'Reilly website , the transformation can be figured out from this.

Web 1.0 --> Web 2.0

DoubleClick --> Google AdSense
Ofoto --> Flickr
Akamai --> BitTorrent
mp3.com --> Napster
Britannica Online --> Wikipedia
personal websites --> blogging
evite --> upcoming.org and EVDB
domain name speculation --> search engine optimization
page views --> cost per click
screen scraping --> web services
publishing --> participation
content management systems --> wikis
directories (taxonomy) --> tagging ("folksonomy")
stickiness --> syndication

The list will go on.What differs is the approach and user Interactivity.What more confusing is that the Web 2.0 has become so widespread that companies are now pasting it on as a marketing buzzword, with no real understanding of just what it means. The question is particularly difficult because many of those buzzword-addicted startups are definitely not Web 2.0, while some of the applications I identified as Web 2.0, like Napster and BitTorrent, are not even properly web applications!
Like most of the concepts , Web 2.0 doesnt have any boundary , but it really have a core engine. I can visualize Web 2.0 as a set of principles and practices that tie together a solar system of sites that demonstrate some or all of those principles, at a varying distance from that core.
If Netscape was the standard bearer for Web 1.0, Google is most certainly the standard bearer for Web 2.0, So let's start with a comparison of these two companies and their positioning. Netscape framed "the web as platform" and the product was mainly based on web browser,a desktop application.They also tried to project "webtop" to replace the desktop concept and planned to populate it with updates and informations.

Google,by contrast, started their sail as a web application,delievered as a service

rather than a commodity,with customers paying directly or indirectly for their

service.There were no scheduled software releases,only continous

improvement.Google requires a competency that Netscape never needed: database

management. Google isn't just a collection of software tools, it's a specialized

database. Without the data, the tools are useless; without the software, the data is

unmanageable.Google's service is not a server--though it is delivered by a massive

collection of internet servers--nor a browser--though it is experienced by the user

within the browser.