Plagiarism is about using creative work without attribution (that is, giving credit.) Plagiarism is using someone else's words (or other creative output) and claiming them as your own or (otherwise not giving them credit). We cite sources (among other reasons) to avoid plagiarizing someone else's work, and to attribute quotations and paraphrasing in our work.
Copyright infringement is about using creative work without permission. Copyright infringement happens whenever we use someone else's creative work without their permission. Does that mean that every time we quote someone in our paper that we need to ask for their permission? No! This is because the copyright law has a concept called "fair use" built into it. You can read all about fair use in this guide, but the kind of quoting that you would do in a paper would nearly always be a fair use.
It is possible to plagiarize without infringing copyright. It is also possible to infringe copyright without plagiarizing.
For more information about plagiarism and academic integrity, visit Academic Integrity.
Images, video, or audio in class presentations in face-to-face classes in a classroom setting is likely permitted, unless the license for the item explicitly forbids it (such as streaming Netflix in a class setting). This broad exception does not apply to copying and distributing text, so doing something like photocopying an article might not be allowed.
We are sometimes asked by students or student clubs if it is okay to show a movie. As a general rule, clubs are not permitted to show movies in a public setting.
There are, basically, two contexts in which you could show a movie without public performance rights (the license that allows you to show a movie legally in public when you are not the copyright owner):
For almost all other showings, you will need to have secured public performance rights in order to show a movie.