An excellent article on Creative Commons was published on CNET, here is a quote to give you an idea…
“Here’s the concept of a Creative Commons license, as I understand it. Every creative work receives copyright protection automatically the moment you fix the work by putting pen to paper, hitting save, or pressing record. This protection reserves all rights to the work’s creator. Nobody can use that work without express written permission except where there is legally determined fair use. (We’ll get to what constitutes fair use in a minute.)
Creative Commons provides a somewhat standardized set of licenses that a creator of copyrighted works can use to give extra rights to people. This is similar to the GPL, used for software. (What was hard for me to wrap my head around in writing this column is that Creative Commons is actually more about protecting the audience you’re hoping will use your work than it is about protecting you. You still hold on to whatever rights you reserve, but you’re abandoning some of those rights on purpose.)
Copyright law protects any creative work you create whether you want it to or not. Nobody can legally use your work beyond fair use without a license. Creative Commons serves as a license that people who want their work to be shared can issue. Don’t want your work to be shared? No problem. Don’t use a Creative Commons license. ”