Sociology is the study of social life, social change, and the social causes and consequences of human behavior. Sociologists investigate the structure of groups, organizations, and societies, and how people interact within these contexts. Since all human behavior is social, the subject matter of sociology ranges from the intimate family to the hostile mob; from organized crime to religious cults; from the divisions of race, gender and social class to the shared beliefs of a common culture; and from the sociology of work to the sociology of sports. In fact, few fields have such broad scope and relevance for research, theory, and application of knowledge.

Sociology provides many distinctive perspectives on the world, generating new ideas and critiquing the old. The field also offers a range of research techniques that can be applied to virtually any aspect of social life: street crime and delinquency, corporate downsizing, how people express emotions, welfare or education reform, how families differ and flourish, or problems of peace and war. Because sociology addresses the most challenging issues of our time, it is a rapidly expanding field whose potential is increasingly tapped by those who craft policies and create programs. Sociologists understand social inequality, patterns of behavior, forces for social change and resistance, and how social systems work.
[From:  American Sociological Association]