Copyright and trademark are the two intellectual-property regimes people confuse most often, and the confusion is expensive: businesses register the wrong thing, sue under the wrong statute, and leave the protection they actually need unclaimed. This article sets the two systems side by side and keeps them there, comparing what each protects, where the right comes from, how long it lasts, which office grants it, what symbols mark it, and how a court measures infringement. It works through six invented but realistic examples—a logo, a jingle, a slogan, a comic-book hero, a mobile app, and a distinctive package—to show where the regimes diverge and where they run through the same object at once. Special attention goes to the boundary the Supreme Court policed in Dastar Corp. v. Twentieth Century Fox, which forbids using trademark as a perpetual substitute for expired copyright, and to the functionality and channeling doctrines that keep each regime in its lane. Every doctrinal point is anchored in primary authority—the Copyright Act, the Lanham Act, and leading Supreme Court and circuit decisions—and in the standard treatises. The payoff is a working framework for deciding which protection you need, when you need both, and where the two rights stop.