Bios Anti-Surge protection

I am currently studying the hardware peripherals as a part of my academic syllabus. I was studying the BIOS and its features now. While studying, I came across a part where it described about the techniques used by the motherboard to protect the peripherals from sudden unexpected power surges. How does a BIOS know if there is any disturbance in supply of power or if any fluctuation has occurred? Is it due to fan underspeeding when such power surge occurs? I couldn’t understand part much, so I need help with it. Is this technique related to BSOD that is found in BIOS menu? Can someone explain me the concept of Anti-Surge protection that motherboard provides?

Almost all the motherboards nowadays have the feature of protecting the peripherals from unexpected power surges when it detects any irregularities in flow of electricity in the system. These issues are created when a user is using neutral connections in the local power grid or neutral connection at your home transformer location. When any such disturbance in power supply is detected, the motherboard shuts itself down leading to sudden turning off the system. If any such power surges are detected, the first victim of its damage would be PSU. Many times, if such problem occurs or your computer has recovered itself out of such problem, then your computer will go in the BSOD mode.