Fundamentally, leadership is a relationship. It is a relationship where you follow someone else by choice, rather than through fear of reprisal or because the other person has one more stripe on their arm than you do. If someone chooses to follow you in pursuit of something you care about when there is no possibility of recrimination or punishment, then you know you have your leadership mojo working!
Viewed in this manner, you can see that leadership is very personal and it shows up everywhere, not just in the office. Do your children follow you because you have the title of “parent”, or do they choose to follow you because of how you relate to them as a human being? This definition also makes a clear distinction between a leader and “the boss”. While the latter uses hierarchy to get the job done, the former uses their way of relating. Of course, the leader may also have hierarchical power; the two terms are not mutually exclusive.