This document discusses groups and teams. It defines groups as two or more people who influence each other, while defining teams as groups committed to a common purpose and mutual accountability. It outlines two types of groups - formal and informal - and reasons people join groups, including security, status, and goal achievement. Key concepts discussed include group norms, which regulate behavior, and cohesiveness, which is dependent on similarities and attraction. The document also outlines types of teams like problem-solving and cross-functional teams, as well as characteristics of effective teams and skills needed to be a team player, such as communication, conflict management, and setting goals.