For a starting point, see Dion Hinchcliffe's review of last year's best explanations. And here, lifted from that source, is a definition which is lifted, in turn, from Tim O'Reilly.
Web 2.0 is the network as platform, spanning all connected devices; Web 2.0 applications are those that make the most of the intrinsic advantages of that platform: delivering software as a continually-updated service that gets better the more people use it, consuming and remixing data from multiple sources, including individual users, while providing their own data and services in a form that allows remixing by others, creating network effects through an "architecture of participation," and going beyond the page metaphor of Web 1.0 to deliver rich user experiences.In other words, it's a techie thing, and you and I don't really understand it. However, it clearly has to do with the internet as it now exists, and as it is developing, and with the growth of new digital ways of doing things. And it has to do with co-operation; and, it would appear, openness and a lack of anally retentive secrecy.
And there are, it seems, lots of people in the world who are thinking about Web 2.0 and what it all means. Though very few of them, as we have often observed, are in the book world.
One such thinker is the afore-mentioned Dion Hinchcliffe, and the Creative Commons blog recently, and rightly, highlighted his essay entitled Thinking in Web 2.0: Sixteen Ways. Of these sixteen thoughts, number five is, I suspect, the one most relevant to you and me. Here it is:
Be prepared to share everything with enthusiasm. Share everything possible, every piece of data you have, every service you offer. Encourage unintended uses, bend over backward to contribute, don't keep anything private that doesn't absolutely have to be. Go beyond sharing and make discovery, navigation easy, obvious, and straightforward. Why: In return, you will benefit many times over from the sharing of others. Note: This is not a license to violate copyright laws, you will not be able to share your ripped DVDs or commercial music recordings, those are things you agreed you can't share. But you might find yourself using and sharing a lot more open source media. And for heaven's sake, learn the Creative Commons license.