There has been a multitude of information about plagiarism and copyright infringement written and reported on, especially now that we are fully entrenched in the internet age. Many people though still mistakenly use the two terms interchangeably. They are not the same. You can have plagiarism without a copyright infringement, and vice versa. This article will attempt to help you understand the differences between the two.
The first step is to define the terms plagiarism and copyright infringement. Plagiarism is taking the writings or ideas of someone else and publishing them as your own without giving credit to the originator. It is a very specific unethical act but NOT illegal in and of itself. A copyright, on the other hand, is a legal protection provided by U.S. and international law to the authors of "original works of authorship" in any tangible medium of expression. The expression may be captured in words, numbers, notes, sounds, pictures, or any other media. The coverage area of copyright law is extremely broad, including literary, dramatic, musical, artistic, audiovisual, and architectural works. Copyright protection is available to both published and unpublished works. Under the Copyright Act of 1976, the copyright owner has the exclusive right to reproduce, distribute, publicly perform and display the work, and produce derivative works.
It is also important to know that there are very limited exceptions under the copyright law that allow uses that would otherwise be illegal. In general, those exceptions are first and foremost, that the owner of the copyright can give it away or sell it to someone else. Although it does happen, more often then not, it is the other exceptions that come into play. For example the "fair use" doctrine, under which a court may excuse unauthorized uses that would otherwise be infringing. Some exceptions under "fair use" are criticism, comment, news reporting, teaching, scholarship, and research. The Copyright Act also contains a number of statutory limitations covering specific uses for educational, religious, and charitable purposes.
So now we have the definitions of plagiarism and copyright infringement, along with copyright law exceptions; what are the main practical differences between the two? Documents in the public domain ARE NOT subject to copyright infringement laws. Just because it is on the internet or the radio though, does not make it public domain. Items in the public domain are works of art, music, literature or any other item of intellectual property that does not belong to anyone specific, but instead belongs to the public in general as historical treasures. The most common examples are government publications and creative works where the copyright has expired. On the other hand, it CAN be plagiarized by using the material without giving credit to the original creator. Using even a small amount of another author's work CAN be plagiarism, but it takes a somewhat substantial amount (the heart), in order to qualify as a copyright infringement. This is a pretty murky area when it comes to what is "substantial" under the law. It isn't a concept of the number of words used, it is more of a concept of whether the heart or substance of the author's work was taken.
* Ideas, concepts, and facts CAN be plagiarized but they CANNOT be copyrighted.