商标 (shāngbiāo) is the formal, legal term for a registered trademark or logo — the official symbol that identifies a company's products and is protected by law. It is more specific than 牌子 (páizi 'brand, sign'), which is the everyday word for a brand name or a physical signboard, and less commercial than 品牌 (pǐnpái 'brand'), which refers to the overall brand image and reputation.