The Web 2.0 entry on Wikipedia gives a snapshot of the many different technologies and topics that exist around it. Take a look at the image they provide:
From Wikipedia, 2006
The Wikipedia entry focuses more on the technologies behind Web 2.0 although it does give some description of the social impact behind it.
I consider this the difference between looking at the invention of the automobile itself versus what automobile-based transportation has done for the world. E.g., inside and outside a car there are many technological innovations: engine, transmission, electrical controls, ergonomics, safety structure, comfort systems, the highway system, etc.
But the impact of this mode of transportation is much wider: the trucking/containerization/delivery industry, suburbization of society, learning to drive (a right of passage of life for many teenagers), leisure travel, car racing, commuting and even telecommuting, etc. are things that have risen from exploding gas within a metal box to turn gears and push carts.
For that same reason, you can certainly be fascinated by the wonders of cars (I certainly spend many hours watching Speed Channel and reading car magazines), but the real impact of having the automobile is so much more.
I see this same difference in Web 2.0 technologies and the value of Web 2.0 itself.
Web 2.0 on Wikipedia