This document summarizes several organizational theories and concepts. It discusses scientific management and human relations approaches from the early 20th century. It also outlines Max Weber's theory of bureaucracy and current trends incorporating new technologies. Key concepts on individual behavior, motivation theories, group dynamics, decision-making models, conflict management, and power/authority are defined. Theories from Maslow, Herzberg, McClelland, Vroom/Yetton, Simon/March/Cyert, and Kilmann on these topics are summarized.