Creative Commons (CC, some rights reserved) is a liberal form of copyright protection that is used in the open access publishing environment.
CC offers different licensing schemes. In some of them, the copyright holders offer some rights to the public to use their work, while other rights are reserved. CC licenses are composed of a combination of several basic features that determine which rights may the copyright holders retain and which they give up.
The four basic features used by Creative Commons are:
Attribution (CC BY) - allows others to distribute, remix, adapt, and build upon a work, even for commercial purposes, as long as they give appropriate credit to the original creator.
Attribution Share Alike (CC BY-SA) - this license element allows the reproduction, display and distribution of the work, even in modified form, while maintaining the original license.
Attribution no Derivatives (CC BY-ND) - allows others to reuse a work, including for commercial purposes, as long as they provide proper attribution to the creator. However, they cannot modify, remix, or create derivative works based on the original.
Attribution Non Commercial (CC BY-NC) - this license element allows the reproduction, display and distribution of the work, however, only if the work will be used for non-commercial purposes.
The combination of the above mentioned four basic features creates other types of Creative Commons licenses. More info >>>