What do you mean by the term ordered pair

An ordered pair is a pair of objects with an order associated with them. If objects are represented by x and y, then we write the ordered pair as <x, y>.

Two ordered pairs <a, b> and <c, d> are equal if and only if a = c and b = d. For example the ordered pair <1, 2> is not equal to the ordered pair <2, 1>.