Ontologies vs Data Models in Graphs — Part 1: The Core Distinction

When you enter the world of graphs and knowledge graphs, two terms appear constantly: **ontology** and **data model**. Sometimes they're used interchangeably. Sometimes they seem like completely different things. This confusion isn't just academic—understanding the distinction directly impacts how you design, build, and reason about graph-based systems. This guide unpacks both concepts, explores the major graph data models you'll encounter, and shows how ontologies and data models work together to create powerful knowledge systems.

Fabisch Kamau·January 20, 2026