Groups consist of 2 or more interacting individuals who share common goals and perceive themselves as part of the group. They form through interaction and developing shared attitudes. Formal groups are created by organizations to fulfill tasks and goals, with defined structures and roles. Informal groups form naturally based on personal similarities and provide social and emotional benefits. High cohesion occurs when members are strongly attached through frequent interaction and shared goals. Teams are small groups with complementary skills committed to common goals and mutual accountability for performance. They enhance productivity through collaborative work.