Here are some of the most common licenses, and how to apply them. This is not legal advice, which should be sought if in doubt.

Attribution means:
You let others copy, distribute, display, and perform your copyrighted work – and derivative works based upon it – but only if they give you credit.

Non-commercial means:
You let others copy, distribute, display, and perform your work – and derivative works based upon it – but for non-commercial purposes only.

No Derivative Works means:
You let others copy, distribute, display, and perform only verbatim copies of your work, not derivative works based upon it.

Share Alike means:
You allow others to distribute derivative works only under a license identical to the license that governs your work.