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 to prevent unsaved work from being lost with a power failure by allowing the user to save work and shut down. If the outage is short, the computer remains running during the outage. The picture shows an APC battery backup power strip.
Having your computer connected to a UPS protects it from electricity surges and outages. When computers shut down improperly, such as when a power outage happens, it can damage the computer's internal parts.
There are three versions of the UPS: standby UPS, online UPS, and line interactive UPS. With a standby UPS (offline UPS), the UPS switches to battery power when the power problem occurs. With an online UPS, the UPS is always providing power from the battery and while they offer better protection are more expensive. For most home users and small businesses, a standby UPS will meet all of their needs.
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.