Venn diagram A schematic representation of a set, first used in the 19th century by John Venn. A universal set U will typically be represented by a rectangle, and a subset S of U by the interior of a circle (or another simple closed curve) lying wholly within the rectangle. Some examples are shown in the diagram. Where appropriate, the shaded areas represent the sets indicated beneath each figure.

Venn di·a·gram / ven/ • n. a diagram representing mathematical or logical sets pictorially as circles or closed curves within an enclosing rectangle (the universal set), common elements of the sets being represented by the areas of overlap among the circles.

Venn diagram In mathematics, diagrammatical representation of the relations between mathematical sets or logical statements, named after the English logician John Venn (1834–1923). The sets are drawn as geometrical figures that overlap whenever different sets share some elements.