Like many important concepts, Web 2.0 doesn't have a hard boundary, but rather, a gravitational core. You can visualize Web 2.0 as a set of principles and practices that tie together a veritable solar system of sites that demonstrate some or all of those principles, at a varying distance from that core.

Check the difference between Web 1.0 and Web 2.0 ..... Web (2.0 - 1.0) = Web 1.0
at http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html

Out of 7 points defined to identify an application as Web 2.0 or Web 1.0 is only one.. i.e.
Web as Platform.

Currently am writing a blog giving me almost every facility thay MS-Word or Star-Word editor gives me, these softwares which we are using on our platform like MS-Windows or any Linux, but are platform dependent... but blogger is not dependant as it is on web.

Checkout Web 2.0 video : http://www.technorati.com/tag/web2.0

By seeing all these scenes we would think that Web is giving lot and fulfilling its actual task that is being means for communication and giving hint that web is making everything free but in actual its giving new shapes and attractive features to vendor's applications which are web applications and Web 2.0 feature reacher... small software company s are making use of these newer things to make space for them.

We'll add more relavant content to this.