Overview
Ontologies in computer science are formal specifications of concepts and their relationships within a domain. They define a shared vocabulary that enables both humans and machines to unambiguously interpret data, reason over it, and share knowledge across systems.
Unlike a taxonomy (which only classifies), an ontology also specifies properties, relationships, constraints, and inference rules.
Key Technologies
- OWL (Web Ontology Language): W3C standard for expressing rich ontologies; enables automated reasoning
- RDFS (RDF Schema): Lighter-weight vocabulary for defining class hierarchies and property domains
- SKOS: Simple Knowledge Organization System — for thesauri, taxonomies, and controlled vocabularies
- SHACL: Shapes Constraint Language — for validating RDF data against ontological constraints
Use Cases
- Biomedical ontologies: Gene Ontology (GO), SNOMED CT — enabling research data interoperability
- E-commerce: Schema.org — structured product/service descriptions indexed by search engines
- Knowledge graphs: Google Knowledge Graph, Wikidata — linking entities across sources
- Enterprise data integration: Common vocabularies for merging heterogeneous databases
Related
- Semantic Web — The broader vision these ontologies serve
- RDF — The data model ontologies build on
- Knowledge Graphs — Practical applications of ontology-described data