A Venn diagram is a diagram showing all possible logical relations between a finite collection of different sets. They depict elements as points in the plane, and sets as regions inside closed curves.
The Venn diagram consists of multiple overlapping closed curves. Usually, these are circles. This documentary shows how a two circle diagram can help you solve problems.
The diagram is an illustration of the relationships between and among sets, groups of objects that share something in common. You can use them to organize information visually and see the relationships.