The term ontology means a formal representation of the real world that “translates” the natural language (ambiguous by its nature) into a formal (unambiguous) language that can be used for the creation of integrated information systems.
Therefore, a computational ontology – for a domain of interest – is a representation:
- formal, expressed in a symbolic non ambiguous language that can be processed by computers;
- shared, resulting from the approval of a plurality, the widest possible, of domain experts;
- explicit, every assumption is made as explicit.
The main advantages of the representation of the domains of interest through ontologies are:
- conceptual representation not requiring the knowledge of how data are physically organized;
- high expressivity, a concept is not a list of attributes but is the recursive composition of logical constructs (intersection, union, complement, disjunction or enumeration of several concepts);
- availability of automatic reasoning tools, more complete and exhaustive information are achievable and more complex and efficient searches can be carried out;
- sharing of knowledge and common vocabularies, achieving semantic interoperability between human-to-human, human- to-machine and machine-to-machine;
- separation between the domain knowledge and the operational knowledge.
The formal language that we used to model the ontologies is OWL – Web Ontology Language that is a W3C (World Wide Web Consortium) standard.
Ontologies are published in several serialization formats including RDF-XML, Turtle and Json-ld formats.