An ordered pair is defined as any pair of numbers for which order is important. Clearly the order of coordinates for a given point is very important for example (5,2) and (2, 5) represent two very different points on a coordinate system. As shown in the image attached. Therefore, a given point such as (5,2), is often referred to as an ordered pair.
"In mathematics, an ordered pair is a pair of objects. The order in which the objects appear in the pair is significant: the ordered pair is different from the ordered pair unless a = b. Ordered pairs are also called 2-tuples, or sequences of length 2; ordered pairs of scalars are also called 2-dimensional vectors."