Re-users must attribute the work to the copyright holder when they use it.
ShareAlike
Re-users who create derivatives of the work must release the derivatives under the same license as the original work, if they choose to distribute the derivatives.
NonCommercial
The work can only be used for non-commercial purposes.
NoDerivatives
Re-users are not allowed to distribute derivatives of the work. Essentially the work cannot be modified.
Re-users must attribute the work to the copyright holder when they use it.
ShareAlike
Re-users who create derivatives of the work must release the derivatives under the same license as the original work, if they choose to distribute the derivatives.