This leadership and management manual concerns organizations of all sizes and all sectors of activity; and its primary objective is to improve performance by answering all the fundamental questions relating to: leadership, management, operations management, business management, international management, human resources, strategic management, project management, risk management, project cost management and control, sustainable development, change management, logistics management, supply management, product management,.... and much more. Overall, this manual provides a set of techniques that make it possible to manage, organize, direct, control and plan the various activities of the company. This manual therefore concerns leadership, management, administration and human resources. If we mix several areas of management, it is because each manager, while sharing the same principles, can have a different conception of the company's priorities. For some, management aims above all to foresee and plan. For others, it is primarily used to resolve problems. For still others, management is essentially a human resources tool whose aim is to ensure the cohesion of teams.