Creative Commons - Attribution (BY)
The CC BY licence lets others distribute, remix, tweak, and build upon the licensed work, even commercially, as long as they attribute the creator as described in the licence. CC BY is recommended to enable access, discovery and use of licensed works.
Creative Commons - Attribution, ShareAlike (BY-SA)
The CC BY-SA licence lets others remix, tweak and build upon the licensed work, even for commercial purposes, as long as they attribute the creator as described in the licence, and licence their adaptations of the work under the same terms. All new works based on the original licensed work will carry the same licence, so any derivatives will also allow commercial use.
Creative Commons - Attribution, No Derivatives (BY-ND)
The CC BY-ND licence lets others redistribute the work, and to make commercial and non-commercial use of the work as long as no alteration is made to the work and the creator is attributed according to the specifications of the licence.
Creative Commons - Attribution, Non-Commercial (BY-NC)
The CC BY-NC licence lets others remix, tweak, and build upon the licensed work for non-commercial use. Any new works created and based on your work must be attributed to the creator as specified in the licence, and may be available for non-commercial use only.
Creative Commons - Attribution, Non-Commercial, ShareAlike (BY-NC-SA)
The CC BY-NC-SA licence lets others remix, tweak, and build upon the licensed work for non-commercial use as long as they attribute the creator of the work under the terms specified in the licence, and licence new creations under identical terms.
Creative Commons - Attribution, Non-Commercial, No Derivatives (BY-NC-ND)
The CC BY-NC-ND licence is the most restrictive of the six Creative Commons licences, only allowing others to download the licensed works and share them with others as long as they attribute the creator as specified in the licence, but users cannot change the work in any way or use it commercially.