This document provides an introduction to sociology, covering its origins, key thinkers and theories. It defines sociology as the scientific study of human social patterns and interactions. The origins of sociology are traced to the 18th-19th century industrial revolutions in Europe and North America. Key founders discussed include Auguste Comte, Herbert Spencer, Karl Marx, Max Weber, Emile Durkheim and others. Major sociological theories summarized are structural functionalism, conflict theory and symbolic interactionism. Research methods in sociology such as surveys, participant observation, case studies and experiments are also outlined.