What is Venn diagram? - Definition from WhatIs.com
Part of the Mathematics glossary:

A Venn diagram is an illustration of the relationships between and among sets, groups of objects that share something in common. Usually, Venn diagrams are used to depict set intersections (denoted by an upside-down letter U). This type of diagram is used in scientific and engineering presentations, in theoretical mathematics, in computer applications, and in statistics.

The drawing is an example of a Venn diagram that shows the relationship among three overlapping sets X, Y, and Z. The intersection relation is defined as the equivalent of the logic AND. An element is a member of the intersection of two sets if and only if that element is a member of both sets. Venn diagrams are generally drawn within a large rectangle that denotes the universe, the set of all elements under consideration.

/WhatIs/images/venn_diagram.gif (4259 bytes)

In this example, points that belong to none of the sets X, Y, or Z are gray. Points belonging only to set X are cyan in color; points belonging only to set Y are magenta; points belonging only to set Z are yellow. Points belonging to X and Y but not to Z are blue; points belonging to Y and Z but not to X are red; points belonging to X and Z but not to Y are green. Points contained in all three sets are black.

Here is a practical example of how a Venn diagram can illustrate a situation. Let the universe be the set of all computers in the world. Let X represent the set of all notebook computers in the world. Let Y represent the set of all computers in the world that are connected to the Internet. Let Z represent the set of all computers in the world that have anti-virus software installed. If you have a notebook computer and surf the Net, but you are not worried about viruses, your computer is probably represented by a point in the blue region. If you get concerned about computer viruses and install an anti-virus program, the point representing your computer will move into the black area.

This was last updated in April 2005
Posted by: Margaret Rouse

Related Terms


  • extrapolation and interpolation

    - Extrapolation is an estimation of a value based on extending a known sequence of values or facts beyond the area that is certainly known. (WhatIs.com)

  • negative correlation

    - A negative correlation is a relationship between two variables such that as the value of one variable increases, the other decreases.  Correlation is expressed on a range from +1 to -1, known as th... (WhatIs.com)

  • Euler diagram

    - 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, altho... (WhatIs.com)


  • Mathematics

    - Terms related to mathematics, including definitions about logic, algorithms and computations and mathematical terms used in computer science and business.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question About Venn diagramPowered by ITKnowledgeExchange.com

Get answers from your peers on your most technical challenges

Tech TalkComment



    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.