http://www.perlmonks.org?node_id=288350


in reply to Tree::DAG_Node

The DAG comes from Directed Acyclic Graph. All the arcs have direction (you can only travel from parent to child, for instance), and the entire graph has no cycles (it isn't possible to travel from a node back to itself without having to retrace the outgoing path). All DAGs can be viewed as trees (or forests, depending on how many connected components you have).