Historically, leadership has been defined as motivating followers to do things they would not otherwise do. In a business or public sector organization, this means getting them to be more productive in their efforts to achieve the organization's goals. On this conception, leadership style refers to the means you use to move your employees to work harder or smarter.
But there was a sea-change in the mid 1970's when the Japanese commercial success in the U.S. caused pundits to call for an end to management, to replace managers with leaders. Unfortunately, we still haven't seen the need to shift our conception of leadership away from its traditional internal focus. As I argued in my recent article, The Number One Job of Leadership, http://businessmanagement.suite101.com/article.cfm/the_number_one_job_of_leadership, it is essential for business success to keep developing new products, new sources of competitive advantage. This means that leaders need to keep a constant eye on their markets and the activities of their competitors. Effective leadership now means continually promoting new ways of beating the competition. This requires an external focus. But if leadership now means successfully promoting better products, then all employees can do it. Those at the top can do, but their primary responsibility is more managerial. In the interests of division of labor, we need to split executive roles into management and leadership. The role of the former is to get things done through people effectively. We won't fully understand leadership until we recognize its new external focus.