A Venn diagram, sometimes referred to as a set diagram, is a diagram that graphically displays all the possible relationships between a finite number of sets. For some very good examples please click the Venn Diagram Picture tab at the top of the page.
At their simplest, Venn diagrams are made up of overlapping circles. The interior of each circle represents a set of objects, or objects that have something in common. The exterior of the circle represents all that each set excludes. The areas where circles overlap show the relationship between sets. For instance, if one circle represents the set “women” and another circle represents the set “politicians” the area of overlap would represent women who are politicians.
Theoretically, a Venn diagram can illustrate the complex relationships between hundreds of sets. As the number of sets grows higher, circles may be replaced by other kinds of closed curves.
As well as having a firmly established place in logic and the “hard” sciences such as mathematics and biology, Venn diagrams have also made their way into the world of literature and composition. A Venn diagram is a handy way to compare and contrast storylines and characters. It can also be used to organize one’s thoughts prior to writing an essay.