You asked me to explain what is Web 2.0 ... Web 2.0 must live it!
The Web2.0, ie the evolution of the web is not easy to explain in words clearly.
To facilitate understanding of the concept we propose an image that compares the
Web 1.0 (year 2000) web2.0 with the year 2007:
Web 1.0 (year 2000) web2.0 with the year 2007:
... but remember that there is already talk of web 3.0! 
