I have seen the discussions of fair use of copyrighted works, and I am still fairly confused about a few things.
How does something like Cliff Notes fall under fair use? Are they not profiting from the intellectual property of the copyright owner, and more specifically, the name and brand recognition of content? I understand brief summaries, quotes or reviews typically fall under fair use, but the entire book is that type of content.
Furthermore, how does something like the Simpsons on Philosophy work?
Are you allowed to write about a subject that may be copyrighted, if what you write is original content?
Is there a difference between writing a new work exclusively about one copyrighted subject, versus writing about it in a collection of similar subjects. For instance, a biography of one politician versus a collection of biographies about politicians.
Thanks for any help you can offer.