# directed graph

A directed graph, also known as a **digraph**, is a graph in which each edge is replaced by a **directed
edge**, indicated by an arrow. A directed graph having no multiple
edges or loops is called a **simple directed graph**. A complete
graph in which each edge is bidirected is called a **complete
directed graph**. A directed graph having no symmetric pair of directed
edges (i.e., no bidirected edges) is known as an **oriented graph**.
A complete oriented graph (i.e., a directed graph in which each pair of
vertices is joined by a single edge having a unique direction) is called
a tournament or tour.