Creative Commons is a nonprofit organization founded in 2001 by Lawrence Lessig and others. The organization is dedicated to expanding the range of materials available online that we can share, repurpose, and build upon. To support this work, Creative Commons developed a set of free and easy to use human and machine readable licenses that allow creators to give broad permissions for how their intellectual property can be used by others.
Creative Commons licenses come in 7 "flavors" ranging from expansive to restrictive. A full explanation of usage rights is available in the chart below, but the general categories of CC licenses are:
BY - Users have broad rights, but must attribute the creator.
SA - In addition to attribution, users must "pay it forward" by publishing any derivatives under the same CC license as the creator.
NC - Users have broad rights, but must provide attribution and cannot use the work for commercial purposes
ND - Users can share the work, but may not adapt, modify, or otherwise create derivatives.
These Licenses may be present in the following combinations: