‘Copper’ can refer to many things, but typically in this context you’d be talking about the elemental metal. That is, the titular copper-colored metal, used often in electronics, and has the properties one usually associates with metals: ductile (can be spun into wires), electrically and thermally conductive, deformable, etc. Cupric sulfate, or copper sulfate, is a salt formed from charged atoms of copper the charged sulfate ions (SO4). As a salt it likewise shares the many properties of salts, such as dissolving easily in water, can be toxic in high doses, and can react with other salts depending on solubility and electrostatic potential.