Short for Uninterruptible Power Supply, UPS is a hardware device that provides a backup power source in case of a power outage (blackout), brownout, or a surge in power. A UPS provides enough power for the computer or computers to shut down properly or to remain up during a temporary power outage or brownout. Above is the Picture of a APC battery backup power strip to help keep a steady flow of power going to the computer.
Other Meaning of UPS is
United Parcel Service, UPS is a standard package and mail delivery service throughout the world.