The Network Diagram is a graphical display of tasks in a project; each task is represented by a small box or node, and lines connect the nodes to show task dependencies. This view is most useful for getting an overall look at how the process or flow of task details fit together.
The Network Diagram is based on the Program Evaluation and Review Technique (PERT), a project management methodology introduced by the U.S. Navy in 1958. The popular version of the Network Diagram used in Microsoft Project reveals information about the individual task, as well as information about the task's place in the flow of activity.