This document defines and discusses organizational behavior. It provides definitions of organizational behavior from various scholars as the study and understanding of how people act within organizations. It outlines different theories of organization, including classical, humanistic, and modern theories. The classical theory treats workers objectively and focuses on efficiency and production, exemplified by Taylor's scientific management and Fayol's 14 principles of management. The humanistic theory allows more worker participation and focuses on needs. Modern theory recognizes limitations of prior approaches and consists of system and contingency theories using an open system framework.