General use

• Kinship
  Kinship
  Kinship is a relationship between any entities that share a genealogical origin, through either biological, cultural, or historical descent. And descent groups, lineages, etc. are treated in their own subsections....
  
  , relationship by genealogical origin
• Social relation
  Social relation
  In social science, a social relation or social interaction refers to a relationship between two , three or more individuals . Social relations, derived from individual agency, form the basis of the social structure. To this extent social relations are always the basic object of analysis for social...
  
  s, in social science, social interaction between two or more individuals
• International relations
  International relations
  International relations is the study of relationships between countries, including the roles of states, inter-governmental organizations , international nongovernmental organizations , non-governmental organizations and multinational corporations...
  
  , strategies chosen by a state to safeguard its national interests and achieve its foreign policy objectives

Logic and philosophy

• Relation (philosophy), links between properties of an object
• Relation (logic), term in set theory and logic, for a property that assigns truth values to k-tuples of individuals
• Relation of Ideas
  Relation of Ideas
  A Relation of Ideas, in the Humean sense, is the type of knowledge that can be characterized as arising out of pure conceptual thought and logical operations . In a Kantian philosophy, it is equivalent to the analytic a priori...
  
  , in the Human sense, is the type of knowledge that can be characterized as arising out of pure conceptual thought and logical operations (in contrast to a Matter of Fact)
• Relational theory
  Relational theory
  In physics and philosophy, a relational theory is a framework to understand reality or a physical system in such a way that the positions and other properties of objects are only meaningful relative to other objects...
  
  , framework to understand reality or a physical system in such a way that the positions and other properties of objects are only meaningful relative to other objects

Computers and technology

• Relation (database)
  Relation (database)
  In relational model:A relation value, which is assigned to a certain relation variable, is time-varying. By using a Data Definition Language , it is able to define relation variables.The following is an example of a heading which consists of three attributes....
  
  , in the relational model of databases, a set of tuples (also called rows), otherwise known as a table (database)
  Table (database)
  In relational databases and flat file databases, a table is a set of data elements that is organized using a model of vertical columns and horizontal rows. A table has a specified number of columns, but can have any number of rows...
  
  
• Ontology components (relation), a component of an ontology
• Binary relation
  Binary relation
  In mathematics, a binary relation on a set A is a collection of ordered pairs of elements of A. In other words, it is a subset of the Cartesian product A2 = . More generally, a binary relation between two sets A and B is a subset of...
  
  , a synonym for dyadic relation and 2-place relation

Mathematics

• Relational algebra
  Relational algebra
  Relational algebra, an offshoot of first-order logic , deals with a set of finitary relations that is closed under certain operators. These operators operate on one or more relations to yield a relation...
  
  , an offshoot of first-order logic (and of algebra of sets), deals with a set of finitary relations (see also relation (database)
  Relation (database)
  In relational model:A relation value, which is assigned to a certain relation variable, is time-varying. By using a Data Definition Language , it is able to define relation variables.The following is an example of a heading which consists of three attributes....
  
  ) which is closed under certain operators
• Relation (mathematics)
  Relation (mathematics)
  In set theory and logic, a relation is a property that assigns truth values to k-tuples of individuals. Typically, the property describes a possible connection between the components of a k-tuple...
  
  , a generalization of arithmetic relations, such as "=" and "<", that occur in statements, such as "5 < 6" and "2 + 2 = 4"
• Ternary relation,finitary relation in which the number of places in the relation is three. Ternary relations may also be referred to as 3-adic, 3-ary, 3-dimensional, or 3-place.
• Theory of relations
  Theory of relations
  The theory of relations treats the subject matter of relations in its combinatorial aspect, as distinguished from, though related to, its more properly logical study on one side and its more generally mathematical study on another....
  
  , treats the subject matter of relations in its combinatorial aspect, as distinguished from, though related to, its more properly logical study on one side and its more generally mathematical study on another

Other uses

• Relational quantum mechanics
  Relational quantum mechanics
  Relational quantum mechanics is an interpretation of quantum mechanics which treats the state of a quantum system as being observer-dependent, that is, the state is the relation between the observer and the system. This interpretation was first delineated by Carlo Rovelli in a 1994 preprint, and...
  
  , an interpretation of quantum mechanics which treats the state of a quantum system as being observer-dependent, that is, the state is the relation between the observer and the system
• Relation (journal), the first newspaper
• Sexual relations, euphemistic term for human sexual activity

See also

• Relationships (disambiguation)
• Relationism
  Relationism
  Relationism can refer to:*In social thought, Karl Mannheim pioneered the idea of Relationism, in the development of his theories on the Sociology of Knowledge...
  
  , can refer to unrelated theories in sociology and physics
• Relativism
  Relativism
  Relativism is the concept that points of view have no absolute truth or validity, having only relative, subjective value according to differences in perception and consideration....
  
  , the concept that points of view have no absolute truth or validity, having only relative, subjective value according to differences in perception and consideration
• Relativity (disambiguation)
  Relativity (disambiguation)
  -Physics:* Special relativity, a theory of physics formulated by Albert Einstein, Henri Poincaré, and Hendrik Lorentz* General relativity, Einstein's theory of gravitation...