| Ontology | Formal representation of the knowledge of a domain: its concepts (nodes), their attributes and the relations that link them. It is the semantic map of your business knowledge, written in English and understandable by the AI agent. | VEHICLE — is_composed_of — BOM — includes — PART |
| Knowledge Graph | An ontology instantiated with real data. The ontology defines the model; the Knowledge Graph is its concrete use. This is what the AI agent queries to answer business questions. | The node “308 VIN-X” is an instance of the VEHICLE type. |
| Reference ontology | Industry standard designed by experts (ETSI, W3C, EU…). Not required for an AI agent, which understands explicit English names, not standard codes. Only useful to reconcile or compare several ontologies. | If used, document it with the reference_standard attribute: "eCl@ss: 27-01-04-01" |
