Complex polygons can be made from polygons that are touching or are completely separate, or can even use one polygon contained completely inside another polygon. Each individual polygon in the group is called an island. An example of islands that can form a complex polygon is the Hawaiian Islands. You can also have one polygon completely inside another polygon. This is referred to as a lake. Lakes form holes in a complex polygon so you can see through the lake to any underlying objects. If one polygon is inside another polygon, the inside polygon becomes a hole inside the larger polygon so you can see through to any underlying objects.
Complex polygons can be separate islands
as shown for Hawaii (top), or can contain lakes
that form holes in the larger area (bottom).