Browse Definitions:

Euler diagram

Contributor(s): Matthew Haughn

An Euler diagram (pronounced OY-ler diagram) is a graphic depiction commonly used to illustrate the relationships between sets or groups; the diagrams are usually drawn with circles or ovals, although they can also use other shapes.

Inclusion is represented by the overlapping of circles – called Eulerian circles -- representing the sets and and subsets. Exclusion is represented by non-overlapping circles. Euler diagrams typically include colors that are blended in areas where the circles overlap. Generally, the size of the circles is not significant but only adjusted to allow for more space for subsets.

Euler diagrams are closely related to Venn diagrams and depending on the sets in question, can look identical. However, in Venn diagrams, overlapped circles don't necessarily indicate a commonality between sets, just a possible logical relationship, unless their labels are in the intersecting circle.

See a simple example, below, of how the relationship between the sets of animals and minerals and the subset of four legs could be depicted in Venn and Euler diagrams:

 Venn Diagram Euler diagram
304px-VennDiagram 300px-EulerDiagram

Euler diagrams, Eulerian circles and Euler’s constant are named for Swiss mathematician Leonhard Euler (1707–1783). Both Venn and Euler diagrams were adopted for teaching set theory as part of the new math movement of the 1960s.

This was last updated in July 2015

Continue Reading About Euler diagram

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.


File Extensions and File Formats


  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

  • pure risk (absolute risk)

    Pure risk, also called absolute risk, is a category of threat that is beyond human control and has only one possible outcome if ...


  • cloud ecosystem

    A cloud ecosystem is a complex system of interdependent components that all work together to enable cloud services.

  • cloud services

    Cloud services is an umbrella term that may refer to a variety of resources provided over the internet, or to professional ...

  • uncloud (de-cloud)

    The term uncloud describes the action or process of removing applications and data from a cloud computing platform.


  • federated identity management (FIM)

    Federated identity management (FIM) is an arrangement that can be made among multiple enterprises to let subscribers use the same...

  • cross-site scripting (XSS)

    Cross-site scripting (XSS) is a type of injection security attack in which an attacker injects data, such as a malicious script, ...

  • firewall

    In computing, a firewall is software or firmware that enforces a set of rules about what data packets will be allowed to enter or...




  • bad block

    A bad block is an area of storage media that is no longer reliable for storing and retrieving data because it has been physically...

  • all-flash array (AFA)

    An all-flash array (AFA), also known as a solid-state storage disk system, is an external storage array that uses only flash ...

  • volume manager

    A volume manager is software within an operating system (OS) that controls capacity allocation for storage arrays.


  • hybrid hard disk drive (HDD)

    A hybrid hard disk drive is an electromechanical spinning hard disk that contains some amount of NAND Flash memory.