2,500 years ago, Sun Tzu in The Art of War distinguished the difference between two leadership/management roles. He called these roles “the general” and “the emperor”. The first was a leader and the second a manager. The two roles are different and use very different methods.
The key differences are a matter of control and goals. A manager has control of his key resources. His goals are to transform inanimate resources into more useful ones: growing food, making products, etc. The methods for doing this are known and largely predictable. He manages people and resources, making sure that the things that need to be done at a certain time get done. We can describe this as planning.
However, the most important resource of a manager those who follow his orders, the people who do the work. He is their boss. Where does his control of these people come from? Why do they obey him instead of some other manager?
In the case of the emperor, the reasons is the general. The general works in a competitive environment, not a controlled one. The key resources, historically control of the land, are contested. He must react to the decisions of others, who he does not control, his rivals, his opponents. His method is not planning but strategy. Using strategy, he convinces his men to fight for him. Using strategy, he outmaneuvers his opponents. In Sun Tzu’s system, a general doesn’t win by fighting, but by creating position that others would rather join than fight.
In today’s competitive environment, we associate leaders with selling and marketing, but the theory is the same. Managers manage what is controlled: a factory, a supply chain. Leaders win what is contested: customers, name recognition, etc.