Both diagrams are based on the set theory. The main difference between Venn and Euler diagrams is that a Venn diagram shows all possible logical relationships between sets, while an Euler diagram only shows existing relationships. In other words, in a Venn diagram you have to depict each intersection between each set, even if the intersection is empty, while in an Euler diagram you only depict intersections that are not empty.
Suppose we have three sets:
Suppose we have three sets:
