# Binary Relation

##### Updated: October 21, 2020

A *binary relation* \(R\) over sets \(X\) and \(Y\) is a *subset* of the cartesian product of \(X \times Y\). Where \(X\) is the *domain*, or set of departure of \(R\), and \(Y\) is the *codomain*, or set of destination of \(R\).

An element \(x \in X\) is related to \(y \in Y\), *iff* the ordered pair \((x, y)\) is found within the (above) subset.