The [[Cardinality]] of a [[Set]] is the number of distinct objects within that [[Set]], denoted as $|S|=n$. The [[Cardinality]] of any [[Set]] is either within the [[Natural Numbers]] or [[Infinity|Infinite]]. >[!tip] [[Finite]] Sets If the [[Cardinality]] of a [[Set]] is within the [[Natural Numbers]], $|S| \in \N$, then that [[Set]] is [[Finite]]. If the [[Cardinality]] between $A$ and $B$ are equal, there exists a [[Bijective|Bijection]] between $A$ and $B$.