Managers play several key roles in organizations, including overseeing daily operations, setting goals, delegating tasks, enforcing policies, and evaluating performance. Effective management styles include directive (close oversight), authoritative (setting a clear vision), affiliative (focusing on employee happiness), participative (encouraging participation in decisions), pacesetting (setting high standards), and coaching (helping employees develop). The most appropriate style depends on the employees, tasks, and current business situation. Overall, managers are responsible for the coordination and success of organizational activities through both management and leadership.