---
tag: 0G0ASKNA6Z
kind: concept
name: Cardinality
aliases: [size-of-a-set, number-of-elements]
msc: ["03E10"]
sources:
  - url: https://en.wikipedia.org/wiki/Cardinality
    locator: lead section
same_as:
  wikidata: Q4049983
  wikipedia: Cardinality
---

## Summary

The cardinality of a set is a measure of its size, the number of its elements.
Two sets have the same cardinality exactly when they are equinumerous.