Sociology is the systematic study of the relationship between the individual and society and of the consequences of difference. In attempting to understand social behavior, sociologists rely on a type of creative thinking referred to as the sociological imagination. The key element of the sociological imagination is the ability to view one's own society as an outsider would.

Sociology is considered a social science, which is quite broad in scope. Sociologists put their imagination to work in a variety of areas, including aging, criminal justice, the family, human ecology, and religion. Sociology focuses on the scientific study of human behavior and is separated from common sense, which tends to be inaccurate and unreliable.

Sociologists employ theories to examine the relationships between observations or data that may seem completely unrelated at first glance. Effective theory may have both explanatory and predictive powers. Early European theorists made pioneering contributions to the development of sociological theory. Auguste Comte (1798–1857) coined the term sociology to apply to the science of society—the study of human behavior. Harriet Martineau (1802–1876) gave special attention to social class distinctions, such as gender and race. Émile Durkheim (1858–1917) focused on understanding behavior within a larger social context, not just in individualistic terms. Additionally, Durkheim suggested that religion reinforces group solidarity. Karl Marx (1818–1883) emphasized the significance of power and analysis of control over resources. For Marx, social inequality is determined by ownership, or lack thereof, of key material resources. Max Weber (1864–1920) argued that who has power was determined not only by social class and control of material resources, but also by—among others—social status and organizational power. These social resources draw their power from people's willingness to obey the authority of another person, which is in turn based on their perception of the legitimacy of that person's right to rule.

Much of the work of Durkheim, Marx, and Weber involves macrosociology, which concentrates on large-scale phenomena or entire civilizations. A later school of sociologists turned away from this approach in favor of microsociology, which stresses the study of small groups and the analysis of our everyday experiences and interactions. Microsociology emphasizes the significance of perception, of how we see others and how they see us. Erving Goffman (1922–1982) popularized a method known as the dramaturgical approach, which compares everyday life to the setting of the theater and stage and sees people as theatrical performers.

Over time, sociologists came to more fully understand and appreciate the consequences that group membership—especially class, race, and gender—has for opportunity. W. E. B. Du Bois (1868–1963) combined an emphasis on the analysis of everyday lived experience with a commitment to investigating power and inequality based on race. Ida Wells-Barnett (1862–1931) was an early feminist. She argued that societies can be judged on whether the principles they claim to believe in match their actions, and found that America came up short regarding principles of equality and opportunity for women and African Americans.

Sociologists categorize and describe the above sociological insights by dividing them into three approaches: functionalist, conflict, and interactionist. The functionalist perspective views society as a living organism in which each part contributes to its survival. The conflict perspective views the social world as being in continual struggle. Karl Marx viewed the struggle as inevitable, given the exploitation of workers under capitalism. The interactionist perspective is primarily concerned with the fundamental or everyday forms of interaction. Sociologists make use of all the perspectives since each offers unique insights into understanding social behavior.

A recurring theme throughout sociology's history has been the idea that sociological theory and research should contribute to positive social change. Jane Addams (1860–1935) was an early female sociologist who combined intellectual inquiry with social service work and political activism for the purpose of assisting the underprivileged.

A variety of sociological careers is available. Applied sociology is the use of the discipline of sociology with the specific intent of yielding practical applications for human behavior and organizations. Clinical sociology is dedicated to altering social relationships or to restructuring social institutions.

University campuses provide a microcosm of globalization, drawing people together from around the world with radically different values, political views, and customs, and give them opportunities to interact. If such interactions are to be meaningful, positive, and respectful, we must learn to use the sociological imagination to better understand ourselves and our culture.