There are six different license types, listed from most to least permissive here:
CC BY: This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use.
CC BY includes the following elements:
BY 
– Credit must be given to the creator
CC BY-SA: This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use. If you remix, adapt, or build upon the material, you must license the modified material under identical terms.
CC BY-SA includes the following elements:
BY – Credit must be given to the creator
SA 
– Adaptations must be shared under the same terms
CC BY-NC: This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format for noncommercial purposes only, and only so long as attribution is given to the creator.
It includes the following elements:
BY – Credit must be given to the creator
NC 
– Only noncommercial uses of the work are permitted
CC BY-NC-SA: This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format for noncommercial purposes only, and only so long as attribution is given to the creator. If you remix, adapt, or build upon the material, you must license the modified material under identical terms.
CC BY-NC-SA includes the following elements:
BY – Credit must be given to the creator
NC – Only noncommercial uses of the work are permitted
SA – Adaptations must be shared under the same terms
CC BY-ND: This license allows reusers to copy and distribute the material in any medium or format in unadapted form only, and only so long as attribution is given to the creator. The license allows for commercial use.
CC BY-ND includes the following elements:
BY – Credit must be given to the creator
ND 
– No derivatives or adaptations of the work are permitted
CC BY-NC-ND: This license allows reusers to copy and distribute the material in any medium or format in unadapted form only, for noncommercial purposes only, and only so long as attribution is given to the creator.
CC BY-NC-ND includes the following elements:
BY – Credit must be given to the creator
NC – Only noncommercial uses of the work are permitted
ND – No derivatives or adaptations of the work are permitted
(This information is taken from the Creative Commons website and reprinted here under the CC Attribution 4.0 license.)