We Define a group as two or more individuals,interacting and interdependent,Who have come together to achieve particular objectives. Groups can be either formal or informal.By a formal group,we mean one defined by the organization's structure,with designated work assignments establishing tasks.In formal groups,the behaviors team members should engage in are stipulated by and directed toward organizational goals. The six members of an airline flight crew are a formal group. In contrast,an informal group is neither formally structured nor organizationally determined. Informal group are natural formations in the work environment that appear in response to the need for social contact.Three employees from different departments who regularly have lunch or coffee together are an informal group. These types of interactions among individuals,though informal,deeply affect their behavior and performance.