The wikipedia definition of Web 2.0 is:
“web development and web design that facilitates interactive information sharing, interoperability, user-centered design and collaboration on the World Wide Web”
What this really comes down to is
1) web based communites and applications such as Facebook,
2) video hosting/sharing sites such as YouTube,
3) blogs such as those from WordPress,
4) mashups (pages using open APIs and data sources to produce results that form a new feature),
5) wikis suchs as WikiWikiWeb or Wikipedia
6) social networking sites such as Facebook and LinkedIn
It’s important to note that Web 2.0 isn’t an upgrade to the existing world wide web’s technical specifications. Rather, it’s a bunch of features collectively termed “Web 2.0″.
Web 2.0 allows users to interact with the web in more than a “read-only” manner. Instead, users can now build interactive applications that use the web as a networking platform. Applications can now be served entirely via a browser.
Sites geared toward Web 2.0 generally include the following features:
1) Search
2) Ad hoc Links
3) Authoring of content
4) Categorization of content by using Tags
5) Algorithms that leverage the web as an application platform (Extensions)
6) Use of RSS to rapidly notify subscribers about content changes via RSS
From a developer’s perspective: Asynchronous JavaScript and XML (Ajax_(programming)), Microsoft Silverlight, Adobe Flash, and Javascript/Ajax frameworks such as Yahoo! UI Library, Dojo Toolkit, Mootools, and jQuery are used as client-side/web browser technologies used in Web 2.0 development. Ajax programming uses JavaScript to upload and download new data from the web server without undergoing a full page reload. An Ajax_(programming) request is typically formatted in XML or JSON (Javascript Object Notation) format, two widely used structured data formats to retreive data without doing a “full page refresh”. When data is received via Ajax, Javascript program then uses the Document Object Model (DOM) to dynamically update the web page based on the new data, allowing for a rapid and interactive user experience.
Microsoft Silverlight and Adobe Flash are other technologies often used in Web 2.0 applications. Microsoft’s Silverlight and Adobe’s Flash are capable of doing many things which are not currently possible in HTML.
All-in-all, Web 2.0 is a very exciting realm of technologies for both – the end user and developers.
