What is a directed graph?

A directed graph is defined by the presence of directed edges that indicate a specific flow or relationship between nodes. In this type of graph, each connection (or edge) points from one node (the source) to another (the target), which allows for the representation of one-way relationships. This directionality is crucial in various applications, such as representing dependencies in a task schedule or pathways in a network. The ability to have directional edges enables more complex structures, as it captures the essence of the relationships between the nodes accurately.

Other options refer to characteristics that do not define a directed graph. For instance, a graph where all nodes are connected without any direction describes an undirected graph, where the relationship is mutual. The option mentioning edges indicating relationships between nodes is too vague and could refer to both directed and undirected graphs. Lastly, the description of a graph including only weighted edges pertains to a specific type of graph (weighted graph) but does not relate to the directional aspect that characterizes a directed graph. This specificity of edges having direction is what sets directed graphs apart from other types.