Offline UPS Availability = low safety Usually operates like a filter and in case of a powerbreak the UPS switches to the Battery operation mode with short transfer time. Low price solution.
	Line Interactive UPS Availability = medium safety Effective against Power failure ,Power surges,sag under and over Voltage protection. Low to medium price range.
best solution	On-Line UPS Availability high-very high safety Double conversion no SSW(Static Switch) high availability Double conversion with SSW very highavailability some Units can run in parallel/redundant mode to become more protection. Price line medium to high