Often quoted in resumes and cover letters, it is a broad and variable quality.
I have taken on the role as leader often, whether it is as a Team Captain of a recreational billiard league, head of a group of canoeists installing thunderboxes in the parks of Ontario, as Controller and head of an accounting department, or as a professional jumping in during times of decision. Probably, mainly, due to the fact that I am a doer.
Over the years, I find my style as more pull vs push, seeking to inspire, empower, and encourage, rather than coerce and command. There are times for the latter, particularly when crisis makes time short and decisions critical and controlled. However, in groups of motivated people, leading from the middle is a very useful technique. Experience also teaches you how and when to use a soft touch, and when to be firm.
Leadership is also about daring to do.