Groups come in many forms and sizes, from small informal groups to large formal organizations. Sociologists define groups as collections of individuals who have some relationship and shared identity. Groups are structured through roles and norms.
There are several types of basic social groups. Primary groups are small and intimate, while secondary groups are larger and more impersonal. Formal groups have clear procedures and roles, whereas informal groups evolve spontaneously. Gemeinschaft groups are traditional and personal, and gesellschaft groups are more specialized and transactional. Other group types include in-groups, out-groups, reference groups, and voluntary associations.
Group size and structure impact group dynamics. Small groups allow direct interaction, while larger groups require formal leadership