One of the license terms in the Creative Commons license is the term non-commercial. While the term is common enough in daily speech it is not always easy to deliniate between commercial and non-commercial activities.
Creative Commons have put together guidelines to help understand how non-commercial should be understood in relation to the license text. But remember:
Please note – these guidelines are not set in stone; they are a draft subject to debate, discussion and refinement by all those who adopt CC licenses and use CC licensed content, ie. you. Let us know what you think. – Mia Garlick