Voronoi diagrams Partition of a plane with N points (sites) into convex polygons such that   Each polygon contains one and only one site   Every point in the polygon is closest to the polygon's site than any other site Also known as Voronoi tessellation or Dirichlet tessellation Polygons are called Voronoi regions or Voronoi cells or Thiessen polygons or Dirichlet domains Vertices of the resulting graph Voronoi vertices Edges are Voronoi edges