Start is called just before any of the Update methods are called.

Start is only called once in the lifetime of the behavior. The difference between Awake and Start is that Start is only called if the script instance is enabled. This allows you to delay any initialization code, until it is really needed.

The Start function is called after all Awake functions on all script instances have been called.

private var myLife : int;
function Start() {
  myLife = 5;
}