Unit1 discusses key concepts in organizational behavior including definitions of organizations and behavior. It describes the nature of people and how individual differences, perceptions, motivation, and desires for involvement impact behavior. It outlines the multidisciplinary nature of OB, drawing from psychology, sociology, anthropology, and political science. Models of OB including McGregor's Theory X and Theory Y are introduced to frame assumptions about employees. Emerging challenges for OB like workforce diversity, globalization, and changing employee expectations are also covered.