Epidemiology is the study of how diseases affect the health and illness of populations. It involves the analysis of the distribution, patterns, and determinants of health-related events, conditions, and states. Epidemiologists use various methods to understand the causes and risk factors of diseases, track outbreaks, and evaluate interventions to control health issues. The ultimate goal is to improve public health by informing policy decisions and preventive measures based on scientific evidence. Key concepts in epidemiology include incidence, prevalence, risk factors, and the use of statistical methods to interpret health data.