Relvar vs. Relation — What's the Difference?

In relational databases, relvar is a term introduced by C. J. Date and Hugh Darwen as an abbreviation for relation variable in their 1995 paper The Third Manifesto, to avoid the confusion sometimes arising from the use of the term relation, by the inventor of the relational model, E. F. Codd, for a variable to which a relation is assigned as well as for the relation itself. The term is used in Date's well-known database textbook An Introduction to Database Systems and in various other books authored or coauthored by him.

A logical or natural association between two or more things; relevance of one to another; connection

A variable that contains a relation, as distinguished from the relation itself.

The connection of people by blood or marriage; kinship.

A person connected to another by blood or marriage; a relative.

The way in which one person or thing is connected with another

The mutual dealings or connections of persons, groups, or nations in social, business, or diplomatic matters

Sexual intercourse.

The act of telling or narrating.

A narrative; an account.

(Mathematics) A correspondence between two sets, consisting of a set of ordered pairs, the first element of each of which is from the first set, and the second element of each of which is from the second set. If A = {1,2} and B = {3,4}, then {(1,3), (1,4)} is a relation from A to B.

(Law) The principle by which an action done on a certain date is treated as having been done on an earlier date. Also called relation back.

The manner in which two things may be associated.

A member of one's extended family; a relative.

The act of relating a story.

(set theory) A set of ordered tuples.

(set theory) Specifically, a set of ordered pairs; a binary relation.

(databases) A set of ordered tuples retrievable by a relational database; a table.

(mathematics) A statement of equality of two products of generators, used in the presentation of a group.

(category theory) A subobject of a product of objects.

(usually collocated: sexual relation) The act of intercourse.

The act of relating or telling; also, that which is related; recital; account; narration; narrative; as, the relation of historical events.

The state of being related or of referring; what is apprehended as appertaining to a being or quality, by considering it in its bearing upon something else; relative quality or condition; the being such and such with regard or respect to some other thing; connection; as, the relation of experience to knowledge; the relation of master to servant.

Reference; respect; regard.

Connection by consanguinity or affinity; kinship; relationship; as, the relation of parents and children.

A person connected by cosanguinity or affinity; a relative; a kinsman or kinswoman.

The carrying back, and giving effect or operation to, an act or proceeding frrom some previous date or time, by a sort of fiction, as if it had happened or begun at that time. In such case the act is said to take effect by relation.

An abstraction belonging to or characteristic of two entities or parts together

The act of sexual procreation between a man and a woman; the man's penis is inserted into the woman's vagina and excited until orgasm and ejaculation occur

A person related by blood or marriage;

An act of narration;

(law) the principle that an act done at a later time is deemed by law to have occurred at an earlier time;

(usually plural) mutual dealings or connections among persons or groups;