Creative Commons offers 6 types of Licenses. More information about the licenses here.
Creative Commons also provides tools that work in the “all rights granted” space of the public domain.
No Rights Reserved
The CC0 tool "enables scientists, educators, artists and other creators and owners of copyright- or database-protected content to waive those interests in their works and thereby place them as completely as possible in the public domain, so that others may freely build upon, enhance and reuse the works for any purposes without restriction under copyright or database."
No Known Copyright
The Public Domain Mark " enables works that are no longer restricted by copyright to be marked as such in a standard and simple way, making them easily discoverable and available to others."