Managers coordinate the work of others to accomplish organizational goals. There are three levels of management: first-line managers oversee non-managers, middle managers oversee first-line managers, and top managers make organization-wide decisions. Managers work in organizations, which are social units that work toward common goals. The main functions of management are planning, organizing, leading, and controlling. Managers make decisions, allocate resources, and direct others. Effective management achieves goals efficiently and effectively.