The Gestalt law of figure and ground
There are 3 generally agreed categories of figure ground relationship, Stable, reversible and ambiguous.
The figure element is clear and obvious against the ground. One typically dominates the composition.
Both figure and ground have equal heirarchy creating uncertaintly and tension, which can lead to interesting and dynamic design.
Elements can be regarded as both figure and ground simultaneously. They form equally demanding shapes, and the person viewing the communication must form an active participant in the decoding.
The most widely used way to employ figure and ground principles is in promoting a messaging heirarchy. If an element, like a proposition or headline, must have ultimate dominance in a piece of communication, try giving it a lot of surrounding space.