# Draft:Cardinality

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**Cardinality** is the number of elements in a set. The cardinality of any finite set is a natural number. Cardinalities of certain sets manifest the **cardinals**, a type of generalization of the natural numbers. Given a set , the cardinality of the set is denoted as .

## Comparing Sets[edit]

Generalizations of "counting" sets are useful in the context of infinite sets: sets with an infinite "number" of elements. Some cardinalities of some infinite sets are bigger than cardinalities of other infinite sets.

### Sets of equal size[edit]

Given two sets, and , if there exists a bijection or , then .