The X&Y theories look at how a manager's perceptions of what motivates his or her team members affects the way he or she behaves.
Your management style is strongly influenced by your beliefs and assumptions about members of your team: If you believe that team members dislike work, you will tend towards an authoritarian style of management, theory X. On the other hand, if you assume that employees like to work and take pride in their job, you will tend to adopt a more participative style, theory Y.
Everyone is different and works in different ways, from their personal life to their professional life. Some people can be more task oriented and are organized, focused on their goals and always looking to complete their to-do list. While others can be more people oriented and focused on their employees and the relationships they have with them to encourage and motivate them to succeed.
I am one of the few that has yet to watch Lost. However, I recently started watching the show and am pretty hooked on that now. I was immediately blown away in the first episode where a plane has crashed on a remote island and everyone is scared, confused, injured, or dead. They then show this man in a suit that looks around the wreckage for a short time and then immediately springs into action. He starts checking on people nearby to see what he can do to help and starts administering CPR which ends up saving the woman's life. He's directing people where to go and what to do and just has this confidence and calmness of what needs to be done and immediately stood out as a strong leader.