Copyright, trademark, and patent are not three names for one thing; they are three separate legal systems that protect three different kinds of value, with trade secret standing quietly as a fourth. This article explains, in plain but rigorous terms, what each regime protects, where its law comes from, how the right is born, how long it lasts, who registers it, what symbol announces it, and how a court actually decides an infringement case. A single invented product, a flagship electric bicycle, is dissected layer by layer to show all four (really five) protections operating on one machine at once. It maps where the regimes overlap and the doctrinal firewalls that keep one from doing another's job. A diagnostic, a timing-trap warning, and an FAQ turn the theory into decisions you can make about a song, an app, a logo, a gadget, or a recipe.