What does each activity in a network diagram represent, with an associated arrow and description?

In project management, specifically when creating network diagrams to illustrate the flow of activities, each activity represented with an arrow signifies the "activity-on-arrow" method. This approach visualizes each task or process in a project as a distinct arrow, with the direction of the arrow indicating the sequence in which the activities should be performed.

The description associated with each arrow provides critical information about the nature of the activity, such as its duration, responsible party, or resources required. This method facilitates a clear understanding of how various activities interconnect and the dependencies between them, allowing project managers and teams to identify workflows and potential bottlenecks in the project timeline.

The other choices, while relevant in their contexts, do not accurately describe the specific method of representing activities in a network diagram with arrows. For instance, "activity-on-node" represents activities by nodes, which would not employ arrows in the same way as described in the question. The "work breakdown structure" serves to organize tasks hierarchically, focusing on deliverables rather than the sequence of actions, and a "task matrix" is a tool used for tracking tasks against various criteria but does not specifically illustrate the flow of activities like the activity-on-arrow diagram does.