Property Graph Model

Distinguishing feature

The distinguishing feature of a property graph is that graph vertices and edges may be decorated with attributes (or properties). In Neo4j parlance, we talk about nodes (for vertices) and relationships (for edges).

We’ll discuss property graphs here from a Neo4j perspective.

Graph elements

The graph elements we’ll talk about are nodes, relationships, and paths, along with their associated IDs, properties, labels, and types.

The diagram here shows some of these graph constructs:

Nodes are shown with optional labels L1, L2, etc., while the required single-value relationship types are shown as T1, T2, etc. Property maps are shown with yellow document icons for nodes and green document icons for relationships. Some paths are shown between various node pairs.

Nodes

Nodes in Neo4j are graph vertices and are allocated a system ID. They might have zero or more user-defined labels associated with them. Labels are used for grouping nodes into sets.

Nodes may additionally have a map of property names and property values associated with them.