Epidemiology is the study of the distribution and determinants of health and diseases in populations. It involves identifying patterns of disease occurrence and risk factors that contribute to these patterns. Epidemiologists use a variety of research methods and statistical tools to investigate the causes of diseases and to develop strategies for disease prevention and control. This field plays a key role in public health decision-making and policy development. Epidemiology also encompasses the study of outbreaks, epidemics, and pandemics, as well as the assessment of healthcare interventions and their impact on population health.