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What is Ontology?

An ontology is a formal, structured model that defines the key concepts in a domain and the relationships between them, allowing data to be organized and interpreted with explicit meaning.

It represents knowledge using classes (categories of things), properties (attributes or relations), and instances (specific examples), often expressed in standardized languages like OWL or RDF.

Ontologies enable machines to perform logical reasoning, infer new facts, and integrate data from different sources by making implicit assumptions explicit and machine-readable.

Unlike simple lists or taxonomies, ontologies support complex relationships, constraints, and rules that capture real-world semantics beyond hierarchical structures.

Example

A medical ontology might define 'HeartDisease' as a subclass of 'CardiovascularCondition' that has properties like 'hasSymptom' linking to 'ChestPain' and 'treatedBy' linking to 'Medication'.

Why it matters

Ontologies power knowledge graphs, semantic search, and interoperable AI systems by giving data explicit meaning, improving accuracy in applications like recommendation engines and intelligent assistants.

Frequently asked questions

A database schema focuses on data storage and structure, while an ontology emphasizes meaning, relationships, and reasoning across domains.