This document provides an overview of surge protection, including: 1) It describes voltage surges and the risk they pose to electronic equipment, explaining that surges are short duration overvoltages that can damage devices. 2) It discusses the basics of alternating current (AC) power and different types of voltage disturbances like surges, sags, and swells. 3) It explains how surge protective devices (SPDs) like metal oxide varistors work to divert surges to ground and protect equipment through clamping the voltage.