Hi,
Can anybody tell me what is the actual meaning of web 2.0 & 3.0 and what is the development style of both of these? What are the specifications and characteristics of both.
And If there is something which I should know about both of these but because of lack of knowledge I couldn't ask then pls suggest me.
Thanks
They're just buzz-words, not technical titles. For instance, with the rise of social websites, it was said that the internet was no longer a monologue-type presentation. Instead, the mass was quickly becoming the result of users creating data, sharing information, and interacting with eachother.
This gave rise to new names on old technologies like AJAX, which started trends in creating asynchronous solutions, making the web appear to be "live," rather than the traditional refresh-model we're all used to.
As stated in the comments, Wikipedia has a much more in-depth look at the topic itself: http://en.wikipedia.org/wiki/Web_2.0
Buzz words indeed, and everyone wants to be the first to define them.
Basically, Web 2.0 is mashups (mixing up data from multiple streams on a single site) and Web 3.0 according to latest opinion I keep hearing is real-time web (like a twitter feed or facebook friend updates, particularly when its ajaxy and feels "alive").
I think Scobleizer calls Web 3.0 the Web 2020, or something along those lines.
More here: http://en.wikipedia.org/wiki/Web_2.0
I agree with Jonathan that we are not talking about some formal product with version number x.y, you won't see a single agreed definition of Web x.0, or be able to buy a single, exhaustive Web 2.0 development kit.
However I do think that there is some value in these terms, in that they draw to our attention that interesting shifts have happened in the landscape. For me Web 2.0 has two dimensions: first, sophisticated browser techniques allied to easily usable services, the result being very nice apps presented via the browser presenting usefully consolidated views of data from several sources. Second, the increased enablement of collaborative working on the web. Blogging, tweeting, review capabaility on eCommerce sites ... the overall effect is more engaging for the user.
Arguably there is little truly new technology in Web 2.0, more a maturing of techniques that we have been using for years. (I did Ajax-style Web Apps 12 years ago) but there comes a point when the norm is noticably richer and more interesting. Many commercial web sites are very nice these days.
So Web 2.0 skills include Java Script, Ajax, Dojo/JQuery, REST services etc.
I don't believe that Web 3.0 is here yet, I see it as a collective itchy feeling that something new is emerging. this question has some indicative answers.
Basically, Web 1.0 was the web as we knew it in the 90's - the static web. Just a lot of data that you can search for and view.
In the past decade, the web has shifted to Web 2.0, which is also known as the social web. Technologies like AJAX and asynchronous communication made it possible to use the web for more than just downloading data. The web has become more interactive. Think of Facebook, Skype, etc.
Web 3.0 is on the horizon and refers to the Semantic web. The semantic web is an evolution of Web 2.0 and Web 1.0 where all data on the web has attached meta-data that gives context to the data. This means that everything on the web becomes more and more connected and eventually makes the move from data to information. In terms of technologies that are going to be used for Web 2.0, look at OWL and RDF. Both of these are just ways of giving context to data.
You'll know that Web 3.0 has arrived when you search for someone and you receive results for that specific person and not just people with the same names. For instance, Google returns to you the person's Facebook page, his LinkedIn page, his blog etc, etc and not just data that matches the search term.
This is a very broad overview of the terms. Take a look at Wikipedia's entries regarding these for more information.
More like "Biz" words designed by evangelists to attract a flock to their seminars and make a lot of money by just talking.
Long long ago in a galaxy far far away I attended a seminar run by a very BLUE chip company and listened to over an hour of nebulous incoherent tech talk. At the end I asked "what does all this mean?" and the speaker answered "It is a statement of direction!" which was greeted by standing ovation from the participants (aka the flock)! 30 years on I still have not figured out what on earth he was talking about.
So, do not quote me but I think Web 3.0 (aka Web 2020) is a "statement of direction".
A very detailed and comprehensive answer was given in the form of an article by Paul Graham of Yahoo!