Signal flow is the route a signal takes through a device or circuit, from input to output. It describes how information moves through components, where it is amplified, filtered, switched, or transformed. In an electromechanical system like a Hammond organ, tracing signal flow helps show how moving parts and electrical paths combine to create the final sound.
In cyber security, understanding signal flow is important because attacks and defenses both depend on it. Malware authors may hijack a signal path, inject false data, or alter control logic by changing how messages move between modules. Defenders use signal-flow analysis to trace where data should travel, spot unexpected branches, and verify that security controls sit in the right place. It is a practical way to map dependencies, find weak points, and detect tampering in hardware, firmware, and software systems.