The term Web 2.0 refers to a perceived second generation of web development and design that aim to facilitate communication, secure information sharing, interoperability and collaboration on the World Wide Web.  Web 2.0 concepts have led to the development and evolution of web-based communities, hosted services and applications.  Web 2.0 websites allow users to do more than just retrieve information. They can build on the interactive facilities of "Web 1.0" to provide "Network as platform" computing, allowing users to run software-applications entirely through a browser.  Users can own the data on a Web 2.0 site and exercise control over that data.  These sites may have an "Architecture of participation" that encourages users to add value to the application as they use it.  This stands in contrast to very old traditional websites which limited visitors to viewing and whose content could only be modified by the site owner.