Public health is a multidisciplinary field focused on protecting and improving population health. It combines sciences like epidemiology with social sciences to address health issues, emphasizing prevention and health promotion. The field tackles health disparities, collaborates across sectors, and prepares for emergencies. Key concepts include epidemiology, health equity, and social determinants of health. Public health differs from healthcare by focusing on populations rather than individuals. Major challenges today include chronic diseases, infectious outbreaks, and health disparities. Various organizations and stakeholders work together to address these issues.