Explanation: A pulse-forming network (PFN) is a specialized electrical circuit, typically comprising inductors and capacitors, engineered to generate a precisely shaped rectangular voltage or current pulse. Its primary function is to store electrical energy and then discharge it in a controlled manner, creating a pulse of a specific, predetermined duration. This direct control over the energy release means the PFN effectively determines the width of the modulating pulses. The pulse repetition rate (how often pulses occur) is determined by the external timing or triggering circuit that initiates the PFN's discharge, not by the PFN itself. While PFNs are LC networks, their fundamental purpose is pulse shaping rather than acting as general high-pass or low-pass filters for a broad range of frequencies.