In the broadest sense of the word, a "leader" is someone who brings people together and guides them toward a common goal. Anyone can tell others what to do, but effective leadership requires much more than the ability to assign tasks to a group.
Throughout history, much has been written about what it means to be a leader. Chinese military general and "Art of War" author Sun Tzu described a leader as one who "cultivates the moral law, and strictly adheres to proper methods and discipline." Nineteenth-century historian Thomas Carlyle believed leaders were born and not made, while English philosopher Herbert Spencer argued that leaders were the result of the society in which they lived.
The decades that followed brought countless studies and research reports that detailed a wide variety of skills, styles and characteristics related to leadership. Researchers at the University of Michigan identified three specific types of leaders (task-oriented, participative and relationship-oriented) in the 1940s and '50s. In the '70s, author Ralph Stogdill named capacity, achievement, responsibility, participation, status and situation as the six categories of personal factors associated with leadership. Research published in the Harvard Business Review in 2000 by author and psychologist Daniel Goleman uncovered six different leadership styles: commanding, visionary, "affiliative," democratic, pace-setting and coaching.