An epidemiological study is a research method used to understand how diseases affect different populations. It examines the distribution and determinants of health-related events, such as infections or chronic illnesses, within specific groups. By analyzing data, researchers can identify risk factors and patterns that help in preventing and controlling diseases. These studies can be observational or experimental. In observational studies, researchers observe subjects without intervention, while in experimental studies, they may manipulate variables to see their effects. Both types contribute valuable insights into public health, guiding policies and interventions to improve community health outcomes.