Leadership can be defined in many ways.  My own view is that a leader is someone who inspires people to do what they otherwise would not do.  I would also say that a true leader is one who inspires people to do good things, but many people might disagree with this.

A leader is not just a person who can force others to do things.  If I stand over someone with a whip and tell them that I will beat them if they do not do their homework, I am not leading them.  I am simply forcing them to comply through the threat of violence.  However, if I inspire them to do their homework, if I make them feel that it is important for them to do their homework, then I am leading them.  I am a leader because I have inspired (rather than forced) them to change their behavior.

I would argue that leadership has something of a moral dimension as well.  I don’t think that people like Hitler should be seen as true leaders even though they did inspire people.  I think that true leadership only exists when the behaviors that are inspired are good ones.