UPS uninterruptible power supply

UPS is uninterruptible power supply or uninterruptible power source UPS or battery  backup is an electrical apparatus that provides emergency power to a load when the input power source typically mains power fails the UPS differs from an auxiliary or emergency power system or standby generator in that it will provide protection from input power supplying energy stored in batteries that it will make 12 volt dc to 220 volt ac from battery