A diagram that graphically shows tasks and their associated links. Tasks are represented by boxes (or nodes), and links are represented by lines that connect the boxes. The PERT Chart is more correctly called a network diagram.
SOURCE; microsoft project glossary-projectlearning.net
A flowchart that shows all tasks and task dependencies. Tasks are represented by boxes and task dependencies are represented by lines connecting the boxes. In a few modern software programs the network diagrams are incorrectly called PERT charts, such as in Microsoft Project.