UPS, or in its long form, uninterruptible power supply, is a power supply that contains a battery that keeps IT running once power is lost.
UPSs also have the capability to help reduce the impact of power surges.
An UPS does not run for too long and should not be confused with a generator. Its main function is to keep systems running until power is restored within a short space of time, or make the transition between a primary power source that has failed to a secondary power source (for example, a generator) that will keep things running for longer.
Essentially, it quickly reacts to a power surge and bridges the transition between primary and backup power sources.
They are used in computers, for example, to give users enough time to save their works before the computer shuts down.
When there is a power surge, the UPS helps prevent the computer being affected and damaged by it.