Creative Commons has been described as being at the forefront of the “copyleft” movement, which seeks to provide an alternative to the automatic "all rights reserved" copyright and has been dubbed "some rights reserved."
Copyleft is a copyright licensing scheme in which an author surrenders some, but not all, rights under copyright law. Instead of allowing a work to fall completely into the public domain, where no ownership of copyright is claimed, copyleft allows an author to impose some restrictions on those who want to engage in activities that would more usually be reserved by the copyright holder. Under copyleft, derived works may be produced provided they are released under the compatible copyleft scheme. There are six licenses as defined at the Creative Common webpage https://creativecommons.org/licenses/.
To encourage maximum dissemination, this sight and its work are covered under the most accommodating of the six. It is called the attribution license and denoted as (CC BY 4.0) and has the following characteristics: