Saybrook University Policy on Authentic Writing and Plagiarism summarizes plagiarism:
"A common violation of authentic writing is plagiarism, in which an individual takes credit for a significant portion of original text prepared by someone else. Similarly, presenting text generated by artificial intelligence as one’s own will also be treated as plagiarism." and "Plagiarism is inconsistent with Saybrook’s humanistic values and incompatible with graduate study."
Why are we quoting the from the Student Handbook? How is plagiarism different from copyright violation?
The difference is cultural ethical practice versus law. In U.S. copyright law, it does not matter if you cite the original author/creator. Plagiarism involves, not just copying other people's work, but not giving them appropriate credit.
In short, it is not Western academic practice to copy other people's work without giving them credit. You can use other people's work, but you should quote and cite appropriately in order to be behaving, not just within accordance with the Saybrook policy, but the ethical practices of the Western world.
On the flip side, if someone, for example, prints 30 copies of the current bestseller and sell them for $1 each because they're a huge fan of the author?? Well, that's not plagiarism, because the author is clear. That's copyright violation!
Need more concrete examples on how to determine whether you are plagiarizing or not? Harvard has some great examples under "
What Constitutes Plagiarism?"