Undirected Graph

A graph for which the relations between pairs of vertices are symmetric, so that each edge has no directional character (as opposed to a directed graph). Unless otherwise indicated by context, the term "graph" can usually be taken to mean "undirected graph."

A graph may made undirected in the Wolfram Language using the command UndirectedGraph[g] and may be tested to see if it is an undirected graph using UndirectedGraphQ[g].