Public copyright licenseA public license or public copyright licenses is a license by which a copyright holder as licensor can grant additional copyright permissions to any and all persons in the general public as licensees. By applying a public license to a work, provided that the licensees obey the terms and conditions of the license, copyright holders give permission for others to copy or change their work in ways that would otherwise infringe copyright law. Some public licenses, such as the GNU GPL and the CC BY-SA, are also considered free or open copyright licenses.
Anti-copyright noticeAn anti-copyright notice is a specific statement that is added to a work in order to encourage wide distribution. Such notices are legally required to host such specific media; under the Berne Convention in international copyright law, works are protected even if no copyright statement is attached to them. However, "anti-copyright" statements typically do not take the form of either sophisticated public copyright licenses or a simple dedication to the public domain; instead, they usually just encourage wide distribution.
Public Domain MarkPublic Domain Mark (PDM) is a symbol used to indicate that a work is free of known copyright restrictions and therefore in the public domain. It is analogous to the copyright symbol, which is commonly used to indicate that a work is copyrighted, often as part of a copyright notice. The Public Domain Mark was developed by Creative Commons and is only an indicator of the public domain status of a work – it itself does not release a copyrighted work into the public domain like CC0.
Wikimedia CommonsWikimedia Commons (or simply Commons) is a media repository of free-to-use images, sounds, videos and other media. It is a project of the Wikimedia Foundation. Files from Wikimedia Commons can be used across all of the Wikimedia projects in all languages, including Wikipedia, Wikivoyage, Wikisource, Wikiquote, Wiktionary, Wikinews, Wikibooks, and Wikispecies, or downloaded for offsite use. As of February 2023, the repository contains over 90 million free-to-use media files, managed and editable by registered volunteers.