You may have heard terms like web. 2.0 or the Read/Write Web thrown around. This refers to the fact that at one time the Internet (or web) was read only. In other words, you could read on it but you could not really write on it other than, say, bulletin boards, now often referred to as forums.
With the invention of the weblog, this changed the nature of the web because now the reader can also become the writer. Along with weblogs, wikis are another apparatus that allows the reader to write and publish on-line.
This ability to instantly publish has drastically changed the nature of the web. Readers are now more involved in the building of content. Rather than reading static pages of information, they can now not only create their own, but they can also become part of a world-wide conversation on any topic.
For more information, there’s an excellent article available on line: “The Read/Write Web.” (.pdf file)