Progressive Enhancement

As seen on Wikipedia

• http://en.wikipedia.org/wiki/Progressive_enhancement

Progressive enhancement is a label for a particular strategy of Web design that emphasizes accessibility, semantic markup, and external stylesheet and scripting technologies, in a layered fashion that allows everyone to access the basic content and functionality of a Web page, using any browser or Internet connection, while also enabling those with better bandwidth or more advanced browser software to experience an enhanced version of the page.