Understanding the Concepts

Some quick refreshers:

Terminology

When people talk about graphs, they don't use the terms dots and lines. Instead, each dot is called a node or vertex, and each line is called an edge.

Formal Definition

A formal definition of a graph is a "data structure that consists of a finite collection of vertices and edges that represents relationships".

Edges

The edges of a graph are represented as ordered or unordered pairs depending on whether or not the graph is directed or undirected.

Edges of a graph might have weights indicating the strength of that link between vertices.