Creative Commons licenses have been created by the non-profit American organisation Creative Commons. CC licenses allow authors to make the distribution of their work easier, by giving other people the right to share, use, and build upon their work. There are several licenses, depending on the rights each author wishes to keep. Each license is represented by a simple pictogram.
Creative Commons licenses do not abolish copyright, they are built upon copyright. They just allow creators and rights holders to decide which usage rights they wish to give to the public, and which ones they wish to reserve. CC licenses can not be revoked: once a CC license has been applied to a work, this work remains under this license as long as the copyright protection lasts.
CC licenses are built on a combination of 4 conditions:
There are 7 different licenses:
CC BY: The most accommodating license. Users can distribute, adapt, translate, build upon the work as long as they credit the author for the original creation.
CC BY-SA: Users can distribute, adapt, translate, build upon the work as long as they credit the author for the original creation and license their new creations under the identical terms.
CC BY-ND: Users can reuse the work for any purpose, including commercially, credit must be provided to the author, and it can not be shared with others in adapted form.
CC BY-NC: Users can reuse and adapt the work, as long as it is not for commercial purposes. They must give credit to the author. Derivative works do not have to be licensed on the same terms.
CC BY-NC-SA: Users can reuse and adapt the work, as long as it is not for commercial purposes. They must give credit to the author. Derivative works must be licensed under identical terms.
CC BY-NC-ND: The most restrictive CC license. Users can not use the work for commercial purposes, they can not share it in adapted form, they must give credit to the author.
CC 0: No copyright, the work is placed in the public domain. But in many countries, including Switzerland, the author can not waive his/her moral rights.
The correct way to indicate that your work is CC-licensed is to add a bit of text stating and linking to the license, such as: "This work is licensed under a CC-BY 4.0 license.", or, for an offline document, "This work is licensed under a CC-BY 4.0 license. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0". You can also add the button of the license.