Attribution: You may copy, distribute, and alter this image however you like, as long as you give credit for it, in the manner requested by the photographer.

Share Alike: If you want to distribute alterations of an image — if, for example, you crop it to put it on your card, you have to allow others to freely use YOUR image, too. It’s sort of a pay-it-forward condition.

Noncommercial: You cannot use any Noncommercially licensed images for your business. No exceptions.

No Derivative Works: You can use these images only if you do not change them in any way.

These four conditions make up six different kinds of Creative Commons license:

Attribution License
Attribution Share Alike License
Attribution No Derivatives License
Attribution Non-Commercial License
Attribution Non-Commercial Share Alike License
Attribution Non-Commercial No Derivatives License