A graph that vividly represents a set and its relationship with a closed curve is called venn diagram (also called Wayne diagram).

For example, the orange circle (set A) can represent all the creatures of a biped. The blue circle (Group B) can represent all flying creatures. The area where the orange and blue circles overlap (called the intersection) contains all flying bipeds, such as parrots. Think of every living thing as a point in this diagram.