Represents a directed graph.
In a directed graph, components have an explicit direction associated with
Directed nodes differentiate between those
adjacent edges that originate at them (outgoing edges ) and those that
terminate at them (incoming edges).
Directed edges differentiate between the node at the
the source of the edge (source node) and the node at the destination of the
edges (destination node).
The following is a figure of an undirected graph, and one of the possible
directed graphs that can be derived from it. Directionality is indicated
by arrow heads on the edges of the graph.
The following information summarizes the relationships in the directed
version of the graph.