Creative Commons licenses are several copyright licenses released on December 16, 2002 by Creative Commons, a U.S. non-profit corporation founded in 2001.

Many of the licenses, notably all the original licenses, grant certain "baseline rights", such as the right to distribute the copyrighted work without changes, at no charge. Some of the newer licenses do not grant these rights.

Creative Commons licenses are currently available in 43 different jurisdictions worldwide, with more than nineteen others under development. Licenses for jurisdictions outside of the United States are under the purview of Creative Commons International.

Original licenses

The original set of licenses all grant the "baseline rights". The details of each of these licenses depends on the version, and comprises a selection of four conditions:

• Attribution (by): Licensees may copy, distribute, display and perform the work and make derivative works based on it only if they give the author or licensor the credits in the manner specified by these.

• Noncommercial or NonCommercial (nc): Licensees may copy, distribute, display, and perform the work and make derivative works based on it only for noncommercial purposes.

• No Derivative Works or NoDerivs (nd): Licensees may copy, distribute, display and perform only verbatim copies of the work, not derivative works based on it.

• ShareAlike (sa): Licensees may distribute derivative works only under a license identical to the license that governs the original work. (See also copyleft.)

Mixing and matching these conditions produces sixteen possible combinations, of which eleven are valid Creative Commons licenses. Of the five invalid combinations, four include both the "nd" and "sa" clauses, which are mutually exclusive; and one includes none of the clauses. The five of the eleven valid licenses that lack the Attribution element have been phased out because 98% of licensors requested Attribution, but are still available for viewing on the website. There are thus six regularly used licenses:

1. Attribution alone (by)
2. Attribution + Noncommercial (by-nc)
3. Attribution + NoDerivs (by-nd)
4. Attribution + ShareAlike (by-sa)
5. Attribution + Noncommercial + NoDerivs (by-nc-nd)
6. Attribution + Noncommercial + ShareAlike (by-nc-sa)

Works protected

Work licensed under a Creative Commons Licenses is protected by copyright applicable law. This allows Creative Commons licenses to be applied to all work protected by copyright law, including: books, plays, movies, music, articles, photographs, blogs, websites.

However, the license may not modify the rights allowed by fair use or fair dealing or exert restrictions which violate copyright exceptions. Furthermore, Creative Commons Licenses are non-exclusive non-revocable. Any work or copies of the work obtained under a Creative Commons license may continue to be used under that license.