Uninteruptible Power Supplies, usually abbreviated to UPS, are an often over-looked, but vitally important part of any mission critical computer system.
The role of a good UPS is to provide battery backup to important electrical equipment such as Network Servers, NAS Drives etc, even TV and Home Entertainment systems. In addition to battery backup, a good UPS intercepts any electrical spikes, such as those from Electrical Storms and Lightning Strikes, and arrest them before they can damage your expensive equipment.
A UPS is far superior to a “Surge Protected” power board as it affords battery backup. By allowing you enough time to shut down your network, Server etc, damage caused to any connected electrical equipment is stopped before it can occur.