Creative Commons licences allow creators to permit others to legally build upon and share work.
Creative Commons (CC) licences are widely used, for example:
CC material must be acknowledged (see below for how to do this).
Creative Commons licences allow some rights to be reserved, and some to be waived, by the creator (commercial use may not be permitted, for example), rather than having 'All rights reserved' as is the case with copyrighted works.
How material may be used will depend on what right the creator has reserved and which they have waived - see the 'Licence Conditions' box below.
Creative Commons is a US non-profit company.
Each right that creators may reserve, or waive, has initials.
The creator of the material must be attributed (acknowledged).
Users may copy, distribute, display, perform, and modify the work, but must licence the work with the same (and not a more restrictive) licence. If they want to use a more restrictive licence they must obtain the creator's permission.
Work cannot be re-used commercially without permission. Normally educational uses are non-commercial.
Work may be re-used, but not modified without permission.
The initials may be combined. For example: