The mathematical term for a set<span> of </span>ordered pairs<span> is a </span>relation<span>. A </span>relation<span> is any </span>set <span>of </span>ordered pairs<span>. The </span>set of all<span> first </span>components<span> of the </span>ordered pairs<span> is called the domain of the </span>relation<span>, and the </span>set of all second components<span> is called the range of the </span>relation<span>.
