The term web 2.0 is used to refer to a new generation of websites that are supposed to let people collaborate and share information online in ways that were not possible before. With web 1.0, most websites consisted of static HTML pages. Later on, developers began to create web pages dynamically by retrieving information from a database and using a programming language to build pages from this information on the fly. With web 2.0 websites are not only dynamic, but also highly interactive.
A lot of the interactivity of web 2.0 websites is made possible by a new programming technique called AJAX (Asynchronous JavaScript and XML). AJAX makes it possible for the web browser to connect to the web server and download small amounts of information in the background. This method is used to download only the parts of a web page that change as a result of user interaction. That way the entire page does not have to be reloaded each time a change is made, resulting in a more responsive website and a more interactive experience for the person visiting the website.
The term web 2.0 was coined by O’Reilly Media in 2004, when they organized the first conference on the subject. There is debate about what constitutes a web 2.0 site. According to the entry for web 2.0 in Wikipedia, web 2.0 websites exhibit some basic characteristics (from Wikipedia):
- “Network as platform”: delivering information and applications entirely through a web browser. A good example is Google Docs and Spreadsheets, a service provided by Google that allows users to create word processing documents and spreadsheets online.
- An architecture of participation that encourages users to add value to the application as they use it. A good example is , a site that tracks popular news stories and blog posts by allowing its users to vote on them. The stories or posts with the most votes rise to the top of the Digg page.
- Social network features: users can easily share information with each other. Most web 2.0 websites allow you to build a network of other users for the purposes of sharing the resources you have stored online. A good example is del.icious, the social bookmarking website where you can store your bookmarks online as well as share them with other del.icio.us users.
- User ownership of information: users can organize and classify information to meet their own needs. Many web 2.0 websites support the use of a folksonomy, a way of using open-ended labels to categorize information. The difference between a folksonomy and a taxonomy is that the labels (also called tags) are created by the same people who contribute the content. An example of a website that supports tagging is Flickr, a website for hsoting and sharing photos online.
- A rich, interactive, user-friendly interface. Some of the most interactive websites online are the map services. For an example, take a look at Google Maps or Yahoo Maps.
