A UPS is an advanced line interactive uninterruptible power system that is designed to protect your equipment like computers and telecommunication systems blackout when power off. Under normal power condition, the UPS filters out all small fluctuations. during electrical power failure the unit immediately switches to its internal battery for continued power feed to the equipment it is linked to, thus allowing the system to be shutdown correctly which, for example on a computer would prevent files from being left open and result in corruption.