Signal-flow graph

A signal-flow graph is like a map that shows how signals travel from one place to another. For example, when you turn on a light switch, the "signal" travels from the switch to the light bulb and the light bulb turns on. In a signal-flow graph, the switch is like a "start point" and the light bulb is like an "end point". In between, there are lines and arrows that show which direction the signal goes.