In discussing a management topic, scholars, educators, practitioners, and the media often toss out the name of a theorist (Taylor, Simon, Weber) or make a sideways reference to a particular theory (bureaucracy, total quality management, groupthink) and move on, as if assuming their audience possesses the necessary background to appreciate and integrate the reference. This is often far from the case. Individuals are frequently forced to seek out a hodgepodge of sources varying in quality and presentation to provide an overview of a particular idea. This work is designed to serve as a core reference for anyone interested in the essentials of contemporary management theory. Drawing together a team of international scholars, it examines the global landscape of the key theories and the theorists behind them, presenting them in the context needed to understand their strengths and weaknesses to thoughtfully apply them. In addition to interpretations of long-established theories, it also offers essays on cutting-edge research as one might find in a handbook. And, like an unabridged dictionary, it provides concise, to-the-point definitions of key concepts, ideas, schools, and figures.