The Six Creative Commons Licenses
The CC-BY license states that reused work can be used for any purpose as long as it includes attribution to the creator of the original work.
The CC-SA license requires that attribution to the creator be included as well as all future licenses that are assigned to reused work must carry similar and/or compatible elements as the original license.
CC-BY-NC requires that reuse is for non-commercial purposes only and that attribution is included.
CC-BY-ND allows for work to be reused, even for commercial purposes, as long as no adaptations have been made and attribution is given to the creator of the work.
CC-BY- NC-SA requires that any reuse of a piece of work must be for non-commercial purposes and any future CC-licenses must carry the same or compatible elements and attribution must be made to the creator of the original work.
CC-BY-NC-ND is the most restrictive of the CC-licenses. This license requires that reuse must be for non-commercial purposes and any adaptations or derivatives of the work cannot be shared. Unadapted material can be reused for noncommercial purposes as long as attribution is given.