This document discusses leadership definitions, theories of leadership, sources of power, and how power is used in organizations. It covers early leadership studies from the 1930s-1940s and theories that developed including the Great Man Theory, Trait Theory, Situational Theory, and Path-Goal Theory. Sources of power come from one's position, personal attributes, and political skills. Power can be used to gain commitment, compliance, or resistance from others and different power bases are more likely to achieve different outcomes. Strategies for developing and maintaining power within organizations are also outlined.