Characterizing a graph from its node and edge properties

There is not a single type of graph. Each of them has specific characteristics, depending on the modeled process. This section describes some of the characteristics of a graph you should question when starting your journey with a new dataset.

Link direction

Links between nodes can be directed (and are then called arcs in graph theory) or undirected (and are called edges).

While graph theory makes the distinction between directed and undirected links in their naming, the graph database vocabulary usually doesn’t, and all links are called edges or relationships, regardless of whether they’re considered directed or not. In a more general way, I’ll stick to the wording used within the Neo4j Graph Data Science Library, which may sound inaccurate to graph theorists.

Undirected graphs include the following:

• Facebook social network: If you are connected to X, X is also connected to you.
• Co...