The note describes the process of group formation. The key elements of groups are 1) individuals who are members of the group and not an arbitrary collection of people, and 2) who are related to one another in some definite way. The study of group is a twentieth century phenomenon, aimed at better understanding of the nature of groups, the laws of their development (the ways in which groups come into being, function, and dissolve) and their interactions with individuals, other groups, and larger institutions.