Public Domain vs Open License

It is important to understand the difference between public domain and open license (such as Creative Commons licenses). They both grant free access to the materials, but the scope and nature are completely different.

Open license does recognize a clear ownership of an intellectual property, whereas the intent of public domain is for the copyright holder to waive copyright ownership in the work. Therefore, users are required to attribute the work to the original authors when using openly licensed materials.

In a way, public domain is the purest form of open/free, since no one owns or controls the material in any way (this sentence is from Public Domain, CC-BY).

Please see the diagram below to see the difference between public domain and open license.

Public Domain	Open License
Copyright ownership is waived.	Copyright ownership is retained.
Author gives away rights to the public to reproduce and distribute creative work.	Author grants broad rights to the public to reproduce and distribute creative work.

If you want more in-depth discussion about public domain, please read Public Domain by James Boyle. And you suspected right-- this book is CC licensed (CC-BY-NC-SA), meaning that you can download the entire book for free.

Please also see the CC licensed comic created to simplify the concept and make it fun at http://web.law.duke.edu/cspd/comics/zoomcomic.html.

Difference between Public Domain, Open License, and All Rights Reserved Copyright

Finally, please see the diagram below to see the difference between open license, public domain and all rights reserved copyright.

Public Domain	Open License	All Rights Reserved Copyright
Copyright ownership is waived.	Copyright ownership is retained.	Copyright ownership is retained.
Author gives away rights to the public to reproduce and distribute creative work.	Author grants broad rights to the public to reproduce and distribute creative work.	Author does not grant rights to the public.
"It is not mine. I give up my right as an author. You don't even have to cite me although I would appreciate it."	"It is mine. But I do allow you to take my material. No need to ask for my permission to use it because it is already granted. Just ensure to make a proper attribution to me."	"It is mine. I do not allow you to take this material and re-purpose it. You definitely need to ask my permission to use it."