# Relation

[https://en.wikipedia.org/wiki/Relation](https://en.wikipedia.org/wiki/Relation)

The term _relation_ most often refers to a binary relation, although ternary or, generally, n-ary relations are also encountered.

A _finitary relation_ or _n-ary relation_ is a set of n-tuples.

Specific types of relations include:

* Binary relation (or correspondence, dyadic relation, or 2-place relation)
* Equivalence relation (reflexive + symmetic + transitive relation)
* Heterogeneous relation, a relation between possibly distinct sets
* Reflexive relation
* Serial relation
* Ternary relation (or triadic, 3-adic, 3-ary, 3-dimensional, or 3-place relation)

Relation may also refer to:

* Directed relation
* Relation algebra, an algebraic structure inspired by algebraic logic
