Juxtaposition.

Albert Einstein. 

Simply stated, juxtaposition means placing things side-by-side. In art this usually is done with the intention of bringing out a specific quality or creating an effect, particularly when two contrasting or opposing elements are used. The viewer's attention is drawn to the similarities or differences between the elements.

Derives from French word "juxtaposition", from Latin iuxtā (“near”) or from Latin iungō (“to join”) + French position (“position”) from Latin pōnō (“to place”).