What term refers to the pairing of two sets of data?

The term that refers to the pairing of two sets of data is "relation." In mathematics, a relation describes a relationship between two sets, where each element of one set is associated with one or more elements of another set. This concept is foundational in set theory and is commonly used to define various mathematical structures.

In more formal terms, a relation can be understood as a subset of the Cartesian product of two sets. For example, if you have set A and set B, the relation is the set of ordered pairs (a, b) where 'a' is from set A and 'b' is from set B. Relations can represent numerous types of relationships, including functions, but they are broader in scope.

By contrast, the other terms relate to different concepts. For instance, an association often implies a correlation or statistical relationship between variables, while a combination typically refers to selecting items from a set without regard to the order of selection. A function is a specific type of relation that assigns exactly one output for each input from the first set, which is a more restrictive definition than a general relation. Thus, the term "relation" accurately encompasses the idea of pairing two sets of data without the restrictions that apply to functions.