• Standby UPS mode offers basic protection, suitable for less critical applications by providing emergency power during outages. • Line-Interactive UPS mode addresses minor power fluctuations without tapping into the battery, making it efficient for areas with frequent voltage. . The article provides an overview of how uninterruptible power supply (UPS) systems work, including their operating modes and key components. Varied in types—Standby, Line-Interactive, and Online—UPS systems cater to a broad spectrum of needs, from home offices to. . In any event UPS are devices providing continuity of power in the event of a power grid anomaly. They can also provide other degrees of power protection. There are 3 UPS technologies and these are offline, line interactive. .