owlDatatypeProperty

owlDatatypeProperty refers to the OWL concept that classifies properties whose values are data values rather than individuals. In OWL 2, properties come in two main kinds: object properties, which link individuals to other individuals, and datatype properties, which link individuals to literals such as strings, numbers, dates, or booleans. The class representing datatype properties is owl:DatatypeProperty, identified by the IRI http://www.w3.org/2002/07/owl#DatatypeProperty. An ontology asserts that a given predicate is a datatype property by declaring it as an instance of this class. Datatype properties are used to attach literal data to individuals.

Semantically, the range of a datatype property is a datatype or literal value, and its domain can specify the class of subjects to which the property may apply. A typical usage pattern includes declaring domain and range constraints, for example: ex:age a owl:DatatypeProperty; rdfs:domain ex:Person; rdfs:range xsd:integer. Then a statement like ex:alice ex:age "30"^^xsd:integer is valid within the ontology. Datatype properties can also be made functional (owl:FunctionalProperty) to express that a subject has at most one value for the property.

OWL 2 distinguishes datatype properties from object properties, which relate to individuals rather than literals. Datatype properties cannot have object-valued ranges, and they are disjoint from object properties. In practice, owlDatatypeProperty is widely used to model attributes such as age, name, height, or date of birth that are represented by data values in a knowledge base.