The following should not be construed as legal advice. Please contact a lawyer if you have legal questions.
Schematically the world of intellectual property can be split into works in the public domain and works subject to national and international copyright law. See the figure at the end for a cursory visual explanation.Read More
We should start by defining the subject of copyright: the creative work. The creative work must be original, creative, and fixed in a tangible medium. It must also fall into one of the eight broad categories of creative works that are protected under copyright (given below). Other categories are not under the protection of copyright, e.g. facts and data, however their expression may be.
There are two main ways a work can be in the public domain. Items in the public domain may be used freely for any purpose. No attribution is legally necessary, however use without attribution may be considered plagiarism.Read More
First, a work is in the public domain if it is not under copyright. Typically, this means it is old enough that the copyright has expired. Note that more recent commentary on an older work may still be protected by copyright, so if you are copying a modern copy of the work with ancillary materials be careful to distinguish between what is in the public domain and what is not.
Second, a work that is under copyright may be dedicated to the public domain by the copyright holder. The work is in the public domain to the extent applicable law allows.
The Creative Commons organization has made two symbols of convenience to indicate these conditions. PD or indicates the first scenario and CC0 or indicates the second.
Learn More from Creative Commons.
Copyrighted works are legally protected from unauthorized copying, modification, distribution, and public performance amongst other uses. Sometimes works protected by copyright may be used in some way without permission from the copyright holder.Read More
Violating copyright and plagiarism should not be conflated. A copyright violation is concerned with legal rights, whereas plagiarism is concerned with ethics. One can commit both, one, or neither. For example, using a large portion of one of Mark Twain’s public domain works without attribution would be considered plagiarism, not copyright violation. But using a contemporary scholar at length without attribution would be both plagiarism and copyright violation. However, quoting a short passage of a contemporary scholar and properly citing it is neither copyright violation nor plagiarism.
Furthermore, copyrighted works may be licensed for particular uses. When a copyrighted work is licensed its use becomes subject to both copyright law and contract law – where there are disagreements contract law typically prevails.
A wealth of copyright information is available from Stanford University Libraries’ Copyright & Fair Use siteShow Less
There are two major kinds of licenses: the more traditional closed licenses and the more recently popular open licenses. Closed licenses generally limit rights or impose restrictions, while open licenses give up rights or remove restrictions. Works under either are still protected by copyright.Read more.
Works under closed licenses may be electronically enforced (for digital works) through the use of so-called Digital Rights Management (DRM) technology. These technologies prevent a work’s distribution, copying, printing, or modification, etc. Works protected in such a way may be considered DRM-limited.
Other closed licenses rely on trust or other less draconian methods of rights enforcement. These licenses don’t use DRM and tend to have liberal within group sharing policies, for example, the SpringerLink database lets an institution’s community download and keep in perpetuity the e-books they provide. These works are often described as DRM-free.
Open licenses come in numerous flavours, but can be broadly divided into Open Access and Open Source licenses, however the distinction is often blurred. Two organizations provide popular models of open licenses: Creative Commons and Free Software Foundation/GNU.
Creative Commons provides six different internationally compatible licenses:
These licenses seek to enable “Four Freedoms”:
The most common one in non-computer science/engineering areas is the GNU Free Documentation License (GFDL). Other licenses are software-focused and include: The GNU Public License and the Lesser GNU Public License.Show less.
While there are many other issues not covered here, hopefully this has helped to disentangle the legally and ethically complex world of intellectual property.
NO LEGAL ADVICE: This text provides general legal information about copyright and licenses for creative works. It does not apply this information to any individual work or specific situation; it is not legal advice, nor is it a substitute for legal advice. Using this text does not create an attorney - client relationship. This text also is not a complete discussion of all legal issues that may arise. The author makes no warranties regarding the general legal information provided herein and recommend that you consult a lawyer if you are unsure of how this information applies to your particular facts.