A [[Binary Operation]] on [[Set|Sets]].
For any two [[Set|Sets]] $A,B$, the [[Cartesian Product]] of $A$ and $B$, denoted as $A \times B$, is defined as the [[Set]] of all ordered pairs $(a,b)$
$\huge
A\times B =
\set{(a,b) \mid a \in A \wedge b \in B }
$
The [[Cartesian Product]] is [[Associative]] but not [[Commutative]].
$\huge \begin{align}
A\times B &\neq B \times A\\
\end{align}$
$\huge A\times\pa{B\times C} = \pa{A\times B}\times C = A\times B \times C$
The [[Cardinality]] of the [[Cartesian Product]] of two [[Finite]] [[Set|Sets]] is equal to the product of the two sets [[Cardinality]].
$\huge
|A|,|B| \in \N \iff
|A\times B| = |A| |B|
$