Security Encyclopedia

Uninterruptible Power Supply (UPS)

An Uninterruptible Power Supply (UPS) is an appliance that providers continuous electricity to an information or other system. A UPS is activated immediately when the main power supply or direct input fails.

An uninterruptible power supply or uninterruptible power source (both, UPS) differs from backup power systems in that a UPS meets an immediate need. Other systems (e.g. backup generators) tend to tolerate electrical downtime before restoring power. A UPS is generally used for telecommunications, data centers, and computer networks when downtime is disruptive, costly, or dangerous.

UPS’s form factor varies with the size of the need. Some are small, low-voltage units that are designed to protect a single server, while others are huge power systems that support corporate or government data centers.


“Enterprises that provide a critical path into other services and other ones that have little tolerance for downtime install a UPS as part of their Business Continuity Plan. A robust BCP often includes reasonable safeguards against electrical downtime through a UPS.”