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# Set Cardinality

**Cardinality** of a set is the size of a set.

For finite sets, the cardinality of a set is the concrete number of elements in a set.

Cardinality of a set $$S$$ is denoted by $$|S|$$, occasionally equated to $$n$$: $$|S| = n$$

An **infinite set** has infinitely many elements, thereby an infinite cardinality

a **finite set**, e.g. $${1,2,3, \dots,100}$$ has finite cardinality (here the element after elipses is called **terminal set member**.

> Definition: The cardinality of S, denoted |S|, is the number of elements in S.