2. Need of Properties
• This world of classes and individuals would be pretty
uninteresting if we could only define taxonomies.
• Properties let us assert general facts about the members
of classes and specific facts about individuals.
• A property is a binary relation. Two types of properties
• Datatype properties, relations between instances of classes and
RDF literals and XML Schema datatypes
• object properties, relations between instances of two classes.
5. Object properties
• When we define a property there are a number of ways to
restrict the relation. The domain and range can be
• The property can be defined to be a specialization
(subproperty) of an existing property.
<rdfs:domain rdf:resource="#Meal" />
<rdfs:range rdf:resource="#MealCourse" />