Everything in this world, including yourself, your emotions, your feelings and senses, all are fully interdependent. Nothing is independent... And yet, we are not smart enough to understand or realise it. Interdependence itself indicates to you that everything is not existing by itself, as it appears to be to you. So, this is Emptiness in the Buddhist philosophy. Emptiness, Voidness or Shunyata, is the thing that is not really existing as it appears to be because of it being interdependent. 

-- His Holiness Gyalwang Drukpa, Jigme Pema Wangchen