Critical graph is a way of looking at a network by analyzing the connections between its parts. It can tell us information about how the different parts of the network are related and how important they are. A critical graph looks like a diagram with circles connected by lines. The circles are the different parts of the network and the lines show how they are connected. By looking at the structure of the graph, we can figure out which parts are most important, which parts are central to the whole system, and which parts can be ignored.