Attribution CC BY
The work can be used and adapted for any purpose (even commercial) provided credit is given to the creator. The most liberal licence.
Attribution-ShareAlike CC BY-SA
Work can be used and adapted provided credit is given, and adaptations are shared under the same (or compatible**) licence.
Attribution-NonCommercial CC BY-NC
The work, or adaptations of the work, can be used only for non-commercial purposes, and credit must be given.
Attribution-NonCommercial-ShareAlike CC BY-NC-SA
The work can be used and adapted for non-commercial purposes provided the creator is given credit and adaptations are shared under the same (or compatible**) licence.
Attribution-NoDerivatives CC BY-ND
The unadapted work can be used for any purpose provided the creator is credited. If adaptations are made, they are for personal use only and must not be shared.
Attribution-NonCommercial-NoDerivatives CC BY-NC-ND
The unadapted work can be used for non-commercial purposes only provided the creator is credited. Any adaptations are for personal use only and must not be shared.
*If you use a CC licensed work without providing attribution, or without meeting other licence terms you are in violation of the licence and your right to use the work ends automatically. Under version 4.0 of the licences if you comply within 30 days then your rights under the licence are reinstated automatically.
**If you are using SA licensed works you should also use a SA licence, or a compatible licence, on any adaptation. A list of compatible licences can be found on the Creative Commons website.
Shaddim; original CC licence symbols by Creative Commons, are licensed under Attribution 4.0. International via Wikimedia Commons