Leadership is a very complex term. When looking at scholars and journals you will find hundreds of possible definitions, many experts trying to identify the characterstics of leaders and infinite discussions about it.
Leadership is really complex and I don't expect to be able to unfold the mysteries of this concept what I will give you one tip that will help you excercise leadership, at least in one possible but also frequent situation.
Who is the leader when you are in a business meeting? This is simple. The leader is the one who's got the marker or chalk, because he "owns" the blackboard. Owning the blackboard means a lot. He doesn't only decides what to write down, but also everyone will see him as the one who makes that decisions. He is the center of the attention.
If he is good, he'll promote rich, valuable and diverse discussions and the team will accomplish their goals for that meeting. But in any case, he'll be seen as the leader for that meeting.
So next time, if you want to be seen as the leader in a business meeting. Just grab the chalk and own the blackboard!!!