Creative Commons provide licenses and public domain tools that give people and organizations a free and standardized way to grant copyright permissions for creative and academic works; ensure proper attribution; and allow others to copy, distribute, and make use of those works.
Creative Commons allows a range of protections around three areas:
Attribution: the most open license; users must credit the originator of the work.
Attribution, No Derivatives: may use the work unchanged with credit to the creator.
Attribution, NonCommercial, ShareAlike: may use the work noncommercially as long as the creator is credited and the new work carries identical license terms to the original.
Attribution ShareAlike: originator must be credited and new work must carry same license terms as original.
Attribution NonCommercial: subsequent works must be non-commercial and acknowledge the creator.
Attribution NonCommerical NoDerivatives: the most restrictive license. Works may be copied and shared with others with credit to the originator, no changes or commercial use are allowed.