Public Domain works are not protected by copyright law and are, therefore, freely available for everyone to use. Works may not be protected by copyright for a number of reasons:
What this means for your academic projects is that you can use as much of the work as you would like to support your instruction, research, publication, creative work, etc. without needing permission from the original copyright owner. Here are some examples of what you can do with public domain works:
Disclaimer: This tutorial on using public domain materials, Creative Commons licensed materials, and copyright law is provided for informational purposes only! I am not a lawyer and cannot provide legal advice. None of what you read in this tutorial should be construed as legal advice. Should you require legal advice, please contact an attorney.
Creative Commons works are works that are still protected by copyright. However, its authors have chosen to allow certain kinds of uses-- such as being able to copy the work or to share it with others-- without the need to seek permission through Creative Commons license agreements.
The best description about the Creative Commons is--of course-- from its own web site, "What is CC?": http://creativecommons.org/about/what-is-cc
Here is a summary of the basic kinds of Creative Commons licenses and the uses that they allow. These definitions are from the "Licenses" page from Creative Commons.
1. Attribution (Abbreviation: BY): This license allows the most kinds of uses. Users may copy, create derivative works, perform, distribute, or display the work without permission; however, users must attribute you as the author in the way that you desire.
2. Non-Commercial (Abbreviation: NC): An author can use this license to ensure that others may use their work, but not make money from using it.
3. No Derivative Works (Abbreviation: ND): This license will allow a user to copy, perform, distribute, or display a work, but they may not create a derivative work. For instance a user may not create a movie based on a book covered under this kind of license.
4. Share Alike (Abbreviation: SA): If you use a work with this kind of license, any derivative work you create must also be covered by the same license.
These four kinds of licenses can be mixed and matched to create a set of use conditions customized to the author's desires.
* Public Domain (Abbreviation: CC0): It is also possible for an author to release their work into the public domain by using this kind of CC license.
Creative Commons licensed works can apply to all formats of works.