UPS may refer to any of the following:
1. 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 a computer(s) to shut down properly or remain functional during the outage. There are three versions of the UPS: standby, on-line and line interactive. The picture shows an APC battery backup power strip.
If you are using a laptop with a working battery, it can serve as a UPS (not a surge protector). If the power were to be lost to the laptop, it would immediately switch over to the laptop battery for power.
2. Short for United Parcel Service, UPS is a package and mail delivery service used worldwide.