This document provides an introduction to the key concepts of sociology. It defines sociology as the scientific study of social structure and human social behavior, with a focus on groups rather than individuals. The sociological perspective looks at behavior through this lens. Key terms defined include perspective, social structure, and sociological imagination. The document outlines how sociology is a social science that studies patterns of group behavior and seeks social rather than individual explanations for events. It discusses the influence of social groups and conformity, and the importance of developing sociological imagination to understand social forces that shape lives.