Voronoi Diagrams are the dual of Delaunay Triangulations and they are highly useful when attempting

to find the nearest point to any given point in an efficient manner. The closest pair of points actually belong to the site of adjacent voronoi cells.

They are usually used in 2D space but can be expanded onto the third dimension like shown above. Each Voronoi cell receives a distinct coloring to help viewers to quickly differentiate one from the other.