Creative Commons helps "achieve the vision of universal access" by providing "a free, public, and standardized infrastructure that creates a balance between the reality of the Internet and the reality of copyright laws."
Through the implementation of Creative Commons licenses and tools, creators can maintain their copyright while allowing particular uses of their work.
For more information see:
http://creativecommons.org/about
CCs signature animated film covers the basics of why they formed, what they do, and how they do it.
This film describes some of CCs early success stories.