Fuse board = fuse box. It’s your car’s electrical safety panel. Every circuit gets a fuse so one short doesn’t burn the whole wiring.
2 main fuse boards in most cars:
1. Under-dash fuse board: Driver/passenger side, knee area. Handles interior stuff - radio, power windows, interior lights, AC
2. Engine bay fuse board: Near battery. Handles heavy stuff - headlights, AC compressor, starter, ECU
What fuses do: If circuit overloads, the thin metal inside fuse melts first. Sacrifices itself to save your wiring + ECU.