This document provides an overview of epidemiological methods and concepts. It defines epidemiology as the study of disease distribution, determinants, and control in populations. Key concepts discussed include agents, hosts, and environments that influence disease occurrence. Descriptive epidemiology aims to describe disease distribution by time, place and person, while analytical epidemiology identifies risk factors. Observational and experimental study designs are classified. The document outlines the scope, aims, history and uses of epidemiology to understand and control health problems.