HV, or high voltage, refers to electrical systems that operate at voltages significantly higher than standard levels, typically above 1,000 volts for alternating current (AC) and 1,500 volts for direct current (DC). High voltage is commonly used in power transmission to efficiently transport electricity over long distances, minimizing energy loss. In the context of electrical engineering, HV systems require specialized equipment and safety measures to handle the increased risks associated with high voltage. This includes transformers, insulators, and circuit breakers designed to manage and protect against electrical faults and ensure safe operation.