Creative Commons (CC) Licenses are the most commonly used open licenses. When Creative Commons licenses are used, the author or creator retains copyright, while allowing others to use the content, with greater or lessor restrictions, without the need to ask permission. The creator can use six standard licenses, immediately put the work into the Public Domain or customize the license further.
Creative Commons licenses are described in three layers:
This spectrum shows the range of permissions and restrictions CC licenses can allow. The six main CC licenses are in the middle, following the Public Domain, CC0, and before traditional copyright.