People join a group for reasons such as avoiding the feeling of loneliness and social exclusion, being accepted by others, gaining status, and achieving success with the group, based on the need of sense of belonging mentioned in Maslow's Hierarchy of Needs. When individuals join groups, they both influence the group with their personal characteristics and are also affected by the structure, behavioral norms and situational conditions of the group. Many features such as the structure and characteristics of the group, individual characteristics of group members, norms of the group, roles, duties and status of the individuals have an impact on group behavior. It is important for the group members and the group leader to work in coordination in order for the group to achieve its goals and ensure its sustainability. In this study, the conceptual framework of individual and situational factors related to group behavior, characteristics of group structure, group development and group outcomes is presented with a holistic approach. The study is considered to be important in terms of providing researchers with a conceptual analysis on group behavior.