CC0 No Rights Reserved gives creators a way to waive all their copyright and related rights in their works to the fullest extent allowed by law. Work released under CC0 is placed in the public domain.
CC Attribution lets others distribute, remix, adapt, and build upon original work, even commercially, as long as they credit the original creator. This is the most accommodating of licenses offered. Recommended for maximum dissemination and use of licensed materials.
CC Attribution Share-Alike lets others remix, adapt, and build upon original work even for commercial purposes, as long as they credit whoever made it and license their new creations under the identical terms. All new works based on the original work will carry the same license, so any derivatives will also allow commercial use. This is the license used by Wikipedia, and is recommended for materials that would benefit from incorporating content from Wikipedia and similarly licensed projects.
CC Attribution No Derivatives lets others reuse original work for any purpose, including commercially. The original form of the work cannot be changed, and credit must be provided to whoever originally made it.
CC Attribution Non-Commercial lets others remix, adapt, and build upon original work non-commercially. New works must also acknowledge the original creator and be non-commercial. Derivative work does not have to be licensed under the same terms.
CC Attribution Non-Commercial Share-Alike lets others remix, adapt, and build upon original work non-commercially, as long as the original creator is credited and new creations are licensed under identical terms.
CC Attribution Non-Commercial No Derivatives is the most restrictive of the CC licenses, only allowing work to be shared in its original form, non-commercially, with credit given to the original creator.