As with all catalysts, the manager's function is to speed up the reaction between two substances, thus creating the desired end product. Specifically, the manager creates performance in each employee by speeding up the reaction between the employee's talent and the company's goals, and between the employee's talent and the customer's needs.
Marcus Buckingham, Curt Coffman (2014). “First, Break All the Rules: What the World's Greatest Managers Do Differently”, p.58, Simon and Schuster