What is the difference between a whole-house surge protector and a Type 3 point-of-use surge protector?

A whole-house surge protector, classified as a Type 1 or Type 2 Surge Protective Device (SPD) per UL 1449 4th Edition, is permanently installed at the main service panel and protects all downstream circuits from external surges originating from utility lines or lightning strikes. It typically handles surge currents of 50 kA to 200 kA per phase and clamps voltage transients to a safe level for hard-wired appliances and branch wiring. In contrast, a Type 3 point-of-use surge protector is a plug-in device with a lower surge current rating, usually between 1 kA and 10 kA, designed to protect sensitive electronics like computers and televisions at the receptacle level. While Type 3 devices offer fine protection for connected equipment, they cannot prevent high-energy surges from damaging the building's electrical infrastructure, making a layered approach with both types the most effective strategy for comprehensive home surge protection.