Copyrights protect the authors of original content. Copyrights are fixed in duration but may be renewed.
Texts, plays, movies, songs, recordings are obvious choices to copyright. Other creations include:
READ ABOUT EDUCATIONAL FAIR USE on this Guide from Stanford University Libraries.
Can I scan or copy the library copy of my textbook? Maybe.
Can the library email me a copy of the textbook chapter I need to read? No, this is not considered Fair Use. Users must make their own copies for personal use.
Will the librarians tell me if I am not within Fair Use? Only if you ask, and what we say is not binding. Legal precedent says it is the responsibility of each user to observe the law, and the library is required to post this notice at our copying stations. Library staff may remind users of their responsibility, but it is not required that we warn users about possible infringement. Any prosecution for infringing copyright or other legal rights using our materials and copiers need not involve the library or library staff.
The Creative Commons copyrights were developed to create a "free, easy-to-use ... simple and standardized way to give the public permission to share and use your creative work - on conditions of your choice" (creativecommons.org). They apply to any kind of work: text, image, audio, software, hardware.
There are three elements to consider:
By using a CC license, you are making a copyright claim. The licenses are listed here from most open to most restricted:
CC BY users give you credit, can alter your work, can redistribute your work for profit commercially
CC BY ND users give you credit, cannot alter your work, can redistribute your work for profit commercially
CC BY NC users give you credit, can alter your work, can redistribute your work only non-commercially
CC BY SA users give you credit, can alter your work, can redistribute your work for profit commercially, must license it just as you have
CC BY NC SA users give you credit, can alter your work, can redistribute your work only non-commercially, must license it just as you have
CC BY NC ND users give you credit, cannot alter your work, can redistribute it only non-commercially
Many teachers use the CC BY NC SA license, which allows their colleagues and students to revise and redistribute their original work for teaching and learning while giving them credit. It does not allow colleagues to publish their revised work commercially without permission.
The Free Software Foundation's copyleft is close to the CC BY SA license.
The concept of copyleft was created with software in mind and is maintained by the Free Software Foundation. It requires that creators first copyright their work, and then add specific language that gives users rights under a General Public License. The work is not free as in no-cost. The gnu.org quick guide to the GPL explains:
"There are four freedoms that every user should have: the freedom to use software for any purpose, the freedom to change the software to suit your needs, the freedom to share the software with your friends and neighbors, and the freedom to share the changes you make. When a program offers users all of these freedoms, we call it free software."