Intellectual property (IP) is the group of laws that protect the works of authors, composers, and other creators of "virtual works."
If you live in the United States, and you create a piece of writing, music, video, or other artwork, then you, as the author, automatically own the "copyright" (the right to copy) your work. This happens regardless of whether you register it somewhere, or put a copyright symbol on it.
There are some situations which may change this fact: for example, if you are getting paid for your time, then the copyright of your work generally belongs to your employer. (Your employment contract may or may not address this. If it doesn't, the rule of thumb is that work done on "company time" belongs to the company.)
You are not allowed to republish work (writing, music, video, artwork, et cetera) without the permission of the copyright holder.
For work that you produce, copyright law gives you the right to license (or give your permission for others to copy) any work that you create. This permission might be based on payment, or it might be free. You can give your permission with caveats: for example, that your work is free to copy as long as you are given credit as the author.
The laws governing "Fair Use" are vague at best. This concept is continually being challenged and refined. Extensive quoting, (with the appropriate reference and attribution) are common in works of analysis and discourse.
Fair use, however, is not a license to get works without paying for them. For example, if I want to use a clip from the movie "Pirates of the Carribean" in my classroom, I still must legally acquire the movie. Fair use does *not* exempt one from paying for the copy of a work. It does not allow one to republish an entire work. It certainly does not allow one to profit from the exemption.
A trademark is a symbol, generally a word or a phrase, such as "McDonald's" that has been registered with the appropriate government agency. This allows the owner of a trademark to prevent its use by others. (For example, if you or I attempted to open a restaurant called 'McDonalds', we would likely be sued for infringement by the registered owner of the trademark.
This doesn't prevent anybody from *using* the trademark in speech or writing. It only allows the trademark owner to protect their brand from copycats and imposters. In general, trademark infringement only occurs in a commercial setting, not an academic one.
A patent is granted by the US Patent Office and grants exclusive rights to make, use, & sell an invention. In exchange for publishing the "recipe", the inventor receives protection from others who would sell or profit from the same or a similar invention.
The concept of patents is established in the US constitution, and is intended to promote inventions. In general, patents don't apply to scholarly works. However, more recently, the concept of "Intellectual Property" and the importance of algorithms, genes, and software has changed the stakes dramatically. The future of patents as they apply to intellectual property is still being written.
Works in the public domain are under the least restrictive license possible. There are no restrictions whatsoever for material in the public domain. This is content that is not owned or controlled by anyone. This means you are free to copy, sell, modify, distribute, remix, etc... as much as you'd like, any work in the public domain.
In the United States, the Public Domain license is automatically granted for any creations older than 70 years after the author's death. After that, copyrighted material reverts to the public domain. (Note that the limit keeps being extended, coincidentally just enough that Mickey Mouse, created in 1928 has never entered the public domain.)
Open Source usually means the following:
* You may copy and redistribute the work.
* You may make changes and redistribute the changed work.
* AS LONG AS your altered version is released under the same rules. That is, you grant others the same permissions to copy, change, and redistribute the work.
Open source originated in the world of software, and could describe any one of a handful of similar licenses. The canonical open source license, the GPL (Gnu Public License) is often referred to as a "copyleft" license because of its posture 180 degrees opposite the traditional "copyright" idea.
Under the GPL, you are allowed to copy and redistribute a work as much as you like so long as your derivatives are also licensed under the GPL. This has the effect of keeping the original work, and all of its variations and improvements, open to the public, for free.
Selling a work under the GPL is not forbidden, but the work must also be distributed freely, which somewhat defeats the purpose.
The open source licenses have been rewritten to make more sense for non-software. The various Creative Commons licenses offer any combination of the following:
Creative commons homepage: http://www.....