Flickr: Creative Commons

Many Flickr users have chosen to protect their work with a Creative Commons license, and you can browse or search through photos under each type of license...

• 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.
• Noncommercial means: You let others copy, distribute, display, and perform your work - and derivative works based upon it - but for noncommercial 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.

... Flickr: Creative Commons