What does and Uninterrupted Power Supply do?

An uninterruptible power supply, also UPS or battery backup, is an electrical power source that provides emergency power to a load when the input power source or mains power fails. In other words when mains supply has an unexpected outage this power source will support the equipment (Generally server or computer) and notify the user the mains power has failed and recommend that they save all important data before a soft shutdown is performed within a specified timeframe. (approx. 3 – 5 minutes from loss of power)