There are 4 Creative Commons Elements to make 6 Licenses:

The Four:

CC BY	CC SA	CC NC	CC ND

Plus Two Combos:

CC NC-SA	CC NC-ND

CC BY: Attribution—Credit the creator, it's just good manners! Additionally, if it is a Creative Commons license, the BY element is mandatory and always attached to every other license. Even if you don't see the BY—it's there

CC SA: Share Alike—Use the same license, please

CC NC: Non-Commercial—Do not sell it, thanks.

CC ND: No Derivatives—Do not change or alter, got it?

CC NC-SA: Don't use commercially and use the same license.

CC NC-ND: Don't you dare use commercially and while we're at it, don't change it any way either.

Click on badges for complete details on each license:

To find out more about how to use the licenses on your own work, see the Citations Tools and Guides tab in the Create OER section of the Open Educational Resources guide.

A Little History of Creative Commons

Copyright owners maintain the exclusive right to do the following:

• Reproduce the work.  (Make copies. This one has become a huge headache in the digital world...see What is Creative Commons?) 
• Make derivative works. (Build upon the work to create new works...for example, a remix or a mashup.)
• Distribute copies to the public by sale or "other transfer of ownership, or by rental, lease, or lending."  (No one can sell your work...without your permission.)
• Perform the work publicly.  (This includes readings of literary works - only the copyright holder has this right.)
• Display the work publicly.  
• Transmit digitally (in the case of audio transmission of sound recordings)

These rights are exclusive to the copyright holder; no one else has these rights for someone else's content, unless the copyright holder gives them the right. Copyright lasts 70 years after the death of the copyright holder (all the many details and particularities about copyright term lengths can be found on Cornell University's Copyright Services: Copyright Term and the Public Domain LibGuide, our Scholarly Communications guide has more info on copy basics and author rights.

Or go straight to the source and read Copyright Law of the United States (Title 17).

What About Fair Use?

Fair use is a legal exemption to the exclusive rights of copyright holders. It is determined on a case-by-case basis and is based on a consideration of the following four factors:

• The purpose and character of the use (including whether it is transformative, commercial, non-profit, or educational)
• The nature of the copyrighted work
• The amount and substantiality of the portion to be used
• The effect upon the potential market for the copyrighted work

Because intention is a part of the consideration, only the user can make the initial assessment of whether their use is fair. For educational purposes the purpose and substantiality of the portion used consider close reflection. 

Using a code of best practices is the best way to determine if your use constitutes fair use. The Center for Media and Social Impact has a library of best practices for fair use best practices that are subject and discipline specific; The Code of Best Practices in Fair Use for Academic and Research Libraries is one that faculty should be consult.

There is a lot of subtlety in Fair Use interpretations, for more information see the Copyright Office’s Information on Fair Use, and Case Index. 

Where Does Public Domain Fit into All This?

In short, public domain does not fit into copyright—public domain is its own kingdom and is not subject to copyright. Once something falls into the public domain it stays there. When copyright expires, (or was moved into the public domain by the owner, see below; or in cases where it never existed because it doesn't apply, see Fair Use, most government documents, facts, etc.; or was forfeited by failure to comply with formalities that may have preexisted current law) a work will move into the public domain making creative and intellectual works available for use. Different countries have different copyright laws which affects when things become a part of the public domain, but in the United States it is generally extended to 70 years after the life the creator. Yes, that's a long time to wait for the public good that public domain makes possible. 

If you are using public domain materials you don't legally have to do anything, however, the clever folks at Creative Commons did make a public domain badge that you can use so that your readers know the status. It's a nice thing to do. And attribute when possible—there's no excuse for rudeness. Click badge for complete details.

But why wait 70 years? What if you want to put your work into the public domain now—just say to the world Have at it! Make cool stuff! Don't even worry about the details of who, what, where, or how—be free my friends! Well, the Creative Commons team thought of that too. They created a mechanism to dedicate your work to the public domain, copyright be damned. It's the CC Zero. But remember, attribution is always the polite thing to do. Click on badge for complete details.

Use of the CC Zero is restricted to the copyright holder, but if that's you, then go right ahead and share your stuff with no strings attached! 

* Parts of the copyright section of this guide were adapted for use from the excellent Kenyon College Copyright Resources: The Basics licensed under CC BY NC