This document discusses organizational behaviour (OB) and its nature and importance. It defines OB as the systematic study and application of knowledge about how individuals and groups act within organizations. There are three key levels of analysis in OB - examining individuals, groups, and the organization. OB is an interdisciplinary field that draws from psychology, sociology, anthropology, and other disciplines to understand human behavior in organizational settings. Understanding OB helps improve interpersonal relationships, predict behavior, encourage employees, and make organizations more effective.