Tim O'Reilly is generally credited with inventing the term, following a conference dealing with next-generation Web concepts and issues held by O'Reilly Media and MediaLive International in 2004. O'Reilly Media has subsequently been energetic about trying to copyright "Web 2.0" and holds an annual conference of the same name. There is, however, some dispute about whether O'Reilly is responsible for the original coinage. Joe Firmage, for instance, used Web 2.0 to describe using the World Wide Web as a platform in 2003.
One of the most significant differences between Web 2.0 and the traditional World Wide Web (retroactively referred to as Web 1.0) is greater collaboration among Internet users and other users, content providers, and enterprises.
Originally, data was posted on Web sites, and users simply viewed or downloaded the content. Increasingly, users have more input into the nature and scope of Web content and in some cases exert real-time control over it. For example, multiple-vendor online book outlets such as BookFinder4U make it possible for users to upload book reviews as well as find rare and out-of-print books at a minimum price, and dynamic encyclopedias such as Wikipedia allow users to create and edit the content of a worldwide information database in multiple languages. Internet forums have become more extensive and led to the proliferation of blogging. The dissemination of news evolved into RSS.
There is no clear-cut demarcation between Web 2.0 and Web 1.0 technologies, hardware and applications. The distinction is, to a large extent, subjective. Here are a few characteristics often noted as descriptive of Web 2.0: