Answer:
Creative Commons licenses provide an easy way to manage the copyright terms that attach automatically to all creative material under copyright. Our licenses allow that material to be shared and reused under terms that are flexible and legally sound. Creative Commons offers a core suite of six copyright licenses. Because there is no single “Creative Commons license,” it is important to identify which of the six licenses you are applying to your material, which of the six licenses has been applied to material that you intend to use, and in both cases the specific version.
All of our licenses require that users provide attribution (BY) to the creator when the material is used and shared. Some licensors choose the BY license, which requires attribution to the creator as the only condition to reuse of the material. The other five licenses combine BY with one or more of three additional license elements: NonCommercial (NC), which prohibits commercial use of the material; NoDerivatives (ND), which prohibits the sharing of adaptations of the material; and ShareAlike (SA), which requires adaptations of the material be released under the same license.
CC licenses may be applied to any type of work, including educational resources, music, photographs, databases, government and public sector information, and many other types of material. The only categories of works for which CC does not recommend its licenses are computer software and hardware. You should also not apply Creative Commons licenses to works that are no longer protected by copyright or are otherwise in the public domain. Instead, for those works in the worldwide public domain, we recommend that you mark them with the Public Domain Mark.