While copyright ensures the legal rights of intellectual property creators, there are cases when material is no longer protected under copyright, such as public domain materials. Additionally, copyright holders can apply a license to their material to allow it to be used in certain ways without getting permission first.
What is the public domain?
Works in the public domain may be used freely without the permission of the former copyright owner. A work of authorship is in the public domain if it is no longer under copyright protection or if it failed to meet the requirements for copyright protection.
Works in the public domain include the following:
- Works published in the U.S. before 1924
- Post-1924 publications that did not satisfy U.S. copyright requirements (typically notice requirements) of the time
- Publications of the U.S. federal government
- Works donated to the public domain by the copyright holder (usually by providing a statement saying anyone may copy the work)
Peter Hirtle created and maintains a useful resource for assessing when specific materials enter the public domain. You can access the Copyright Term table on the Cornell University Library Page.
How do licenses work?
Licenses grant you permission to do something.
A driver’s license means you’re allowed to drive a car as long as you obey the rules of the road. Similarly, a copyright license can allow you to reuse someone else’s work as long as you follow the rules laid out in the license.
For your digital project, you almost certainly won’t need to request or secure a license for any copyrighted content on your own.
Instead, it’ll be easier for you to search for content that is already licensed for reuse in some way.
It’s important to remember that licenses don’t replace copyright; they just provide another layer on top of existing copyright protections. Additionally, if you want to do something with licensed materials that isn’t covered by the license, such as sell an image when the license prohibits commercial use, you still have to get permission first.
Creative Commons licenses
Creative Commons licenses (CC) make it easy for content creators to share the things they make by clearly and simply defining how other people can use them. There are several licensing systems that exist that allow for this level of control, but CC licenses are by far the most common.
If you want to reuse something with a Creative Commons license, there are four different restrictions that may apply:
- Attribution (BY): all Creative Commons licenses have attribution requirements, which gives credit to the original creator. If you included a poem with a CC-BY license in a book you wrote, you would need to include an attribution with the author’s name.
- Noncommercial (NC) : you can’t make money from the use of the work. If you found a picture that was licensed under CC-BY-NC and wanted to put it on a t-shirt, you couldn’t sell the shirts without asking for permission first.
- No Derivatives (ND): you can’t make changes (derivatives) to the work. If you found a song with a CC-BY-ND license, you couldn’t chop it up into your own new song without asking for permission first.
- Share Alike (SA): you can create a derivative work, but you have to use the same license as the original. If you found a video with a CC-BY-SA license, you could use parts of it in a new video that you create, and even sell it, but your new creation has to have the same CC-BY-SA license.
A note on Share Alike: With the ND and SA restrictions, you cannot have both of them together on the same license. So a CC-BY-NC-ND-SA license cannot exist under Creative Commons terms. The SA restriction only applies to derivative works.
There is unofficially a CC0 (zero) license, but this just indicates that it is in the public domain.
This video quickly outlines how Creative Commons licenses work.
