Venn diagrams, also known as a set diagrams or logic diagrams, visually represent the relationship between two or more subjects consisting of two or more circles that overlap in the middle.

Rotate a two-circle Venn diagram by 180 degrees (or a three-circle one by 120 degrees), and it looks the same. But the four-ellipse diagram doesn’t have rotational symmetry.

Venn diagrams are very useful constructs made of two or more circles that sometimes overlap. Venn diagrams frequently appear in different areas of mathematics but are most common when dealing with ...

Circles that do not overlap have no common traits. The Venn diagram was popularized by mathematician John Venn in the 1880s and is still widely used.