What exactly Web 2.0 means.

Web 2.0 is a term describing the trend in the use of World Wide Web technology and web design that aims to enhance creativity, information sharing, and, most notably, collaboration among users. These concepts have led to the development and evolution of web-based communities and hosted services, such as social-networking sites, wikis, blogs, and folksonomies.

Web 2.0 is the business revolution in the computer industry caused by the move to the Internet as platform, and an attempt to understand the rules for success on that new platform.

Web 2.0 websites typically include some of the following features/techniques:

• Cascading Style Sheets to aid in the separation of presentation and content
• Folksonomies (collaborative tagging, social classification, social indexing, and social tagging)
• Microformats extending pages with additional semantics
• REST and/or XML- and/or JSON-based APIs
• Rich Internet application techniques, often Ajax-based
• Semantically valid XHTML and HTML markup
• Syndication, aggregation and notification of data in RSS or Atom feeds
• mashups, merging content from different sources, client- and server-side
• Weblog-publishing tools
• wiki or forum software, etc., to support user-generated content
• Internet privacy, the extended power of users to manage their own privacy in cloaking or deleting their own user content or profiles.