Web 2.0 is often spoken of as a future goal, but the truth is that the change from Web 1.0 to Web 2.0 is in many ways indefinable. The change is a gradual transition from the read only web, web 1.0 to the read, write, web, web 2.0. The focus has shifted from companies to communities.
Web 2.0 is enables the engagements with content for which users have control over. Users who essentially participate in open source software sites such as Wikipedia have changed the traditional industry structure of production. This is a fundamental movement from the web 1.0 of ownership to the web 2.0 framework for sharing. Users involved in online communities have become their own producers, sharing content, knowledge and ideas to adopt a bottom up approach to content, rather than the traditional top down.
Web 2.0 allows for incremental changes, enabling the improvement in quality of content and material produced. The structure is flexible and the only organising element is the process of development and content creation.
Social communities, therefore create their own structures based on the opinions, views and concepts created by those that are part of it. There are no predetermined structures in the web 2.0 structure, where as web 1.0 relies on a framework.