Cardinality

Noun

1. The number of elements a given set contains.

   "The empty set has a cardinality of zero."

2. The number of terms that can inhabit a type; the possible values of a type.
3. The property of a relationship between a database table and another one, specifying whether it is one-to-one, one-to-many, many-to-one, or many-to-many.
4. The status of being cardinalitial