A Cardinality

1. (set theory, of a set) The number of elements a given set contains.
2. (data modeling, databases) 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.
3. (religion) The status of a cardinal.

Usage notes

(set theory): The cardinality of an infinite set is an infinite cardinal number. The smallest such number, called aleph-null and denoted ℵ₀, describes the natural numbers; the next is aleph-one. While it is known that the cardinality of the real numbers is greater than aleph-null, it is the subject of the still unproven continuum hypothesis that it equals aleph-one.

Synonyms

• (in set theory): power