雇主 (gù zhǔ) is a formal term for 'employer' — the person or organization that hires workers. It is more specific and formal than 老板 (lǎo bǎn), which can also mean 'boss' or 'owner' in a broader sense (e.g., your boss at work, or the owner of a shop). Use 雇主 when referring to the employer-employee relationship, especially in official or business contexts.