UPS (Uninterruptible Power Supply) systems provide backup power during power cuts or interruptions. There are two main types: standby UPS, which only activates during power failure, and online UPS, which continuously provides power from both mains and batteries to connected devices. A UPS is essential for mission-critical systems such as servers, workstations, and data centre infrastructure. Proper UPS sizing is crucial, especially when adding or changing servers, storage, or network switches. Changes in power consumption can impact UPS runtime during power outages, making correct sizing vital for optimal protection.