This document provides an overview of organizing theories. It defines key terms like organization and theory, and discusses the evolution of organizing theory from classical to modern approaches. The classical theories focused on efficiency and included scientific management, bureaucratic, and administrative approaches. Neoclassical theory emphasized human relations. Modern theories view the organization as an open system that adapts to its environment, including the systems approach, socio-technical theory, and contingency theory. The document categorizes and explains different organizing theories.