Epidemiology is a necessary part of public health practise. The study of disease in populations is known as epidemiology. In order to explore risk factors for zoonotic disease in both human and animal populations, veterinarians and others in the preventive medicine and public health professions use epidemiological approaches for disease surveillance, outbreak investigation, and observational studies. The application of hazard analysis critical control point (HACCP) systems is heavily reliant on epidemiological data. For disease surveillance, epidemiological methods are utilised to determine which threats are the most serious. Epidemiological studies are also utilised to identify risk variables that could be crucial control points in public health.