Web 2.0 refers to a second generation of web-based services that emphasize user-generated content, interoperability, and collaboration. These services include social networking sites, wikis, communication tools, and tagging systems that allow content to be distributed, combined, and displayed in new ways. Blogging was an early form of Web 2.0 that broke down barriers to participation by enabling commenting and crowd interaction. Web 2.0 emphasizes information sharing and putting power in the hands of individual users through collaboration and flow of information. It provides new opportunities for on-demand access to information, as well as collaboration among teachers, students, parents, and communities.