Defining Zen is like trying to describe the taste of honey to someone who has never tasted it before. You can try to explain the texture and scent of honey, or you can try to compare and correlate it with similar foods. However, honey is honey! As long as you have not tasted it, you are in the illusion of what honey is. The same goes with Zen because Zen Buddhism is a practice that needs to be experienced, not a concept that you can intellectualize or understand with your brain. The stories that are given here won't cover all of what of Zen is, but is a starting point to the Zen experience.