Web 2.0 is the latest trendy buzzword that is supposed to denote the Second Generation of the Internet. Whilst the concept of defining a behemoth like the Internet in terms of version numbers is a little crazy, there is no escaping the actual concept behind Web 2.0 - essentially, encouraging website and software authors to interact with their visitors to create a truly "interactive" experience.
A great example of "Web 2.0" is the online encyclopaedia Wikipedia. As well as being one of the biggest (free) collections of information on the Internet, it is also created entirely "By the People, For the People". What that means is that the articles are all written, administered and edited by the web users and surfers.
Other examples of things that are generally considered “Web 2.0” include Social Networking, Folksonomies, RSS Feeds, Open Source Software, Consumer Review Portals, File Sharing, Podcasting and Blogs.
Almost 50% of brand marketers will target social networking sites this year, according to Jupiter Research.