A PEO acts as a co-employer and shares responsibility for HR tasks like payroll, benefits, compliance, and risk management. This helps companies reduce the administrative burden of HR responsibilities and provides access to better employee benefits. In contrast, HR (Human Resources) typically refers to the internal department or function within a company that manages hiring, employee relations, and day-to-day workforce management. To summarize, HR is your in-house team handling employee matters, and a PEO steps in as a co-employer to take on many of those complex HR and administrative responsibilities that would otherwise take up a lot of time.