I mean, it's in the name. The right to make copies. Not to be glib, but it really is

A copyright is a type of intellectual property that gives its owner the exclusive legal right to copy, distribute, adapt, display, and perform a creative work, usually for a limited time.

You may notice a conspicuous absence of control over how a copied work is used, short of distributing it. You can reencode it, compress it, decompress it, make a word cloud, statistically analyze its tone, anything you want as long as you're not redistributing the work or an adaptation (which has a pretty limited meaning as well). "Personal use" and "fair use" are stipulations that weaken a copyright owner's control over the work, not giving them new rights above and beyond copyright. And that's a great thing. You get to do whatever you want with the things you own.

You don't have a right to other people's work. That's what copyright enables. But that's beside the point. The owner doesn't get to say what you use a work for that they've distributed to you.