Creative Commons licensed works are free to use, but you must follow the terms of reuse. Check the text of the full deeds (links below) to understand the scope and/or restrictions of the licenses:
Summary: Allows others to distribute, remix, tweak, and build upon your work, even commercially, as long as they credit you for the original creation. This is the most accommodating license offered and is recommended for maximum dissemination and use of licensed materials.
Attribution-ShareAlike CC BY-SA 2.0 Generic
Summary: Allows others to remix and build upon your work, even for commercial purposes, as long as there is proper attribution and the new work is issued under the same licensing terms. This license is often compared to “copyleft” free and open source software licenses.
Attribution-NoDerivs CC BY-ND 2.0
Summary: Allows redistribution of works for both commercial and non-commercial purposes, as long as it is passed along unchanged, in whole, and with proper attribution.
Attribution-NonCommercial CC BY-NC 2.0 Generic
Summary: Allows others to remix and build upon your work non-commercially. Although the new works also must acknowledge the creator and carry a non-commercial license, the new or derivative works created do not have to carry the same terms.
Attribution-NonCommercial-ShareAlike
CC BY-NC-SA 4.0
Summary: Allows others to remix and build upon your work non-commercially, as long as proper attribution is followed and new works are licensed under the same terms.
Attribution-NonCommercial-NoDerivs
CC BY-NC-ND 2.0 Generic
Summary: Allows others only to download your work and share it for non-commercial purposes as long as the work remains in its original format. This is the most restrictive of the licenses.
Summary: Allows creators to waive most copyrights to their original works, allowing others to reuse, share, and remix freely with proper citation. This is the least restrictive of the licenses.
