A UPS (Uninterruptible Power Supply) is an essential device that provides emergency backup power to a load when the main power source fails. It differs from a traditional standby generator in that it offers near-instantaneous power, preventing a temporary interruption that could be damaging to sensitive electronic equipment. The core of a UPS system consists of a battery bank, a rectifier to charge the batteries, and an inverter to convert the stored DC power back into AC power for the connected load. Modern UPS systems often include surge protection and voltage regulation features, ensuring that the connected equipment receives clean and stable power. They are a critical component for data centers, hospitals, and any application where continuous operation is non-negotiable.