A voltage stabilizer is an electrical device designed to maintain a constant voltage level to electrical equipment. It protects appliances from voltage fluctuations, which can cause damage or reduce efficiency. By automatically adjusting the voltage, it ensures that devices receive the appropriate power supply. These stabilizers are commonly used in homes and industries where sensitive equipment, such as computers and medical devices, require stable voltage for optimal performance. They come in various types, including automatic voltage stabilizers and servo-controlled stabilizers, each suited for different applications and power requirements.