Negative space: the area between and around a subject in art. Defining boundaries by the empty spaces, providing context. 
When viewing an artwork, the negative space is the unsung hero of a work- often going unnoticed entirely - but vital to the composition and even the narrative of a work. The name itself, “negative”, seems to create a hierarchy of value, yet mastering effective use of negative space can make all the difference between an effective or awkward composition.