I know that according to a question asked by another user here Are the Apple text-to-speech voices copyrighted?

"Voices is permitted by this License, including but not limited to the use, reproduction, display, performance, recording, publishing or redistribution of any of the System Voices in a profit, non-profit, public sharing or commercial context."

But what is that License? Is it a patent or is it copyright? What kind of protection does the license include? At what point do these protections actually limit use?

I am considering Radiohead's Fitter Happier song for instance.