This document discusses social groups and social organizations. It defines social groups as units of interacting individuals defined by roles and statuses. Social organizations are collectivities established to pursue specific aims, with formal rules and structures. It categorizes groups based on ties, purpose, location and organization. Primary groups like family have strong ties, while secondary groups like work are more impersonal. Formal groups are deliberately formed with defined goals, while informal groups arise spontaneously from interactions. Leadership, qualities of effective leaders, and leadership styles are important influences on group dynamics.