Inspiration from the web:

Leadership is a quality a person may have. One can categorize the exercise of leadership as either actual or potential:

  • actual – giving guidance or direction, like a teacher being a leader to a student, as in the phrase “the emperor has provided satisfactory leadership”.
  • potential – the capacity or ability to lead, as in the phrase “she could have exercised effective leadership”; or in the concept “born to lead”.

Leadership can have a formal aspect (as in most political or business leadership) or an informal one (as in most friendships). Speaking of “leadership” (the abstract term) rather than of “leading” (the action) usually implies that the entities doing the leading have some “leadership skills” or competencies.
Arieu defines a leader as “someone able to inspire another associate with a dream.”