The Property Graph Model

The most popular graph model variant. A property graph is made up of nodes, relationships, and properties.

• Nodes contain properties: Arbitrary key-value pairs where keys are strings and values are arbitrary data types. Think of nodes as documents.
• Relationships connect and structure nodes. A relationship always has a direction, a label, a start node, and an end node: There are no dangling relationships. Direction and label together add semantic clarity.
• Both nodes and relationships can hold properties. Relationship properties are particularly useful for:
  • Providing metadata for graph algorithms.
  • Adding semantics (quality, weight).
  • Constraining queries at runtime.

graph LR
    A["Person<br>{name: 'A', age: 30}"] -->|"KNOWS<br>{since: 2020}"| B["Person<br>{name: 'B', age: 25}"]

Simple enough to be intuitive, yet expressive enough for the vast majority of graph use cases. These primitives are all that’s needed to create sophisticated, semantically rich models.