The document discusses the history and definition of Web 2.0. It notes that Web 2.0 emerged as a term after the dot-com crash in 2001 to describe the evolution of the World Wide Web. The document summarizes Tim O'Reilly's definition of Web 2.0 as focusing on services rather than packaged software, leveraging collective intelligence through user participation, and delivering software as a continually updated service. O'Reilly described Web 2.0 as realizing the true potential of the web by delivering rich user experiences through an architecture of participation across connected devices.