Creative Commons is a non-profit organization founded in 2001. They created the Creative Commons License in 2002 which is a free copyright law that can be applied to photographs, wrtten works, movies, and music for example.

There are different copyright options under Creative Commons to choose from:

• Attrbution (by)
• Noncommercial (nc)
• No Derivative Works (nd)
• Share Alike (sa)

Sources:

http://en.wikipedia.org/wiki/Creative_Commons_licenses