There are six Creative Commons Licenses:
Attribution (CC-BY) - Anyone is free to remix, redistribute, and even commercially use your work, so long as the new work attributes the original work and its author.

Attribution-ShareAlike (CC-BY-SA) - Anyone is free to remix, redistribute, and even commercially use your work, so long as the new work attributes the original work and its author and the new works are shared under the same license. This keeps all material derived from your original work to also be open.

Attribution Non-Commercial (CC-BY-NC) - Anyone is free to remix and redistribute your work, but not commercially, so long as the new work attributes the original work and its author.

Attribution-NonCommercial-ShareAlike (CC-BY-NC-SA) - Anyone is free to remix and redistribute your work, but not commercially, so long as the new work attributes the original work and its author and the new works are shared under the same license. This keeps all material derived from your original work to be both open and non-commercial.

Attribution-NoDerivs (CC-BY-ND) - Anyone is free to redistribute your work, even commercially, so long as the new work attributes the original work and its author. Remixes and other derivative works are not allowed.

Attribution-NonCommercial-NoDerivs (CC-BY-NC-ND) - Anyone is free to redistribute your work, but not commercially, so long as the new work attributes the original work and its author. Remixes and other derivative works are not allowed.
**As noted in the graphic to the left, CC licenses with the ND element are not generally considered OER, since they cannot be changed, only free to share. They are the "least open" before traditional copyright.
Content adapted from "Open Licensing and Creative Commons" by Affordable Learning Georgia, licensed under CC BY 4.0.
Images by creativecommons.org - http://creativecommons.org/about/downloads