In Buddhism it is called Kong (空), in Taoism it is called Xu (虛) or Wu (無). All talking about the same thing: "Emptiness" which is rich in meaning. The silent note in music, the pause and suspense in which nothing happens in drama.
Language is of no use here. The quickest way to understand the power of Negative space, or Kong or Wu, is to pick up a piece of paper and a pencil, and draw a negative space arising from a physical object. No wonder art-forms such as drawing can be very therapeutic. It is easier than reading the Diamond Sutra in most cases, and probably more enjoyable too.... :)