🟢Node

NEW

Also known as: Vertex

A vertex in a graph representing an entity, object, or concept that may have properties and relationships.

DESCRIPTION

Nodes (vertices) are the fundamental units in graph structures, representing entities like people, products, or concepts. They connect via edges to form networks. In property graphs, nodes carry labels and key‑value properties; in RDF, nodes include IRIs, literals, and blank nodes. Node-focused metrics (degree, centrality) support analysis of importance and connectivity. Nodes underpin graph databases, knowledge graphs, and graph machine learning.

ALTERNATIVE DEFINITIONS

Wikipedia

In graph theory, a vertex (plural vertices) or node is the fundamental unit of which graphs are formed.

Establishes the vertex as the core building block of graphs.

Source

Apache TinkerPop

A vertex is an entity that can have properties and be incident to edges in a property graph.

Defines vertices in the labeled property graph context with properties.

Source

Neo4j

In the property graph model, nodes are entities with labels and properties that connect to other nodes via relationships.

Adds labels and relationships as first-class aspects of nodes.

Source

RELATED TERMS

Graph Property Graph Adjacency Graph Database Knowledge Graph Neighbor Degree Subgraph Triple

COMPETING TERMS

Edge

RELATIONS

• Narrower: Blank Node

KNOWLEDGE AREAS

Semantic & Knowledge Modeling Data Modeling AI Data Architecture Data Science

TARGET AUDIENCE

Data Modeler Data Architect AI Engineer Data Scientist Software Developer

EXTERNAL SOURCES

• Wikipedia - Vertex (graph theory)
• Apache TinkerPop - Graph elements reference
• Neo4j - Property graph concepts
• NetworkX - Graph class API for nodes

TOP QUESTIONS

What does a Node represent in a property graph?

It represents an entity, labeled and described by key‑value properties, connected to others by edges.

Category: Concepts

How do Nodes differ between property graphs and RDF?

Property graphs use labeled nodes with properties; RDF nodes are IRIs, literals, or blank nodes in triples.

Category: Comparison

What attributes are commonly stored on a Node?

Identifiers, labels or types, and properties like names, timestamps, or numeric features.

Category: Practice

What is node degree and why is it useful?

Degree counts incident edges; high degree can indicate hubs or influential entities.

Category: Metrics

How are Nodes indexed in graph databases?

By labels and property keys for fast lookup, often with composite indexes and constraints.

Category: Operations

What are common mistakes when modeling Nodes?

Overusing nodes for values that should be properties, which increases graph complexity.

Category: Mistakes

How do Nodes feature in graph machine learning?

They hold features for GNNs to aggregate via neighborhood message passing.

Category: AI

Can Nodes exist without edges?

Yes, isolated nodes are allowed, though they may be less useful analytically.

Category: Concepts

How do Node labels support governance?

Labels map to business types or domains, enabling access control and validation rules.

Category: Governance