When we talk about Voronoi diagrams, it is good to start with understanding what a Voronoi diagram is. Wikipedia provides a nice short explanation of this:

*In mathematics, a Voronoi diagram is a partitioning of a plane into regions based on distance to points in a specific subset of the plane. That set of points (called seeds, sites, or generators) is specified beforehand, and for each seed there is a corresponding region consisting of all points closer to that seed than to any other. These regions are called Voronoi cells.*

In other words, we define a set of points on a 2D surface (for example, the screen), and the Voronoi diagram divides the surfaces into cells based on their distance to each of the points. It's easiest ...