Power distribution units (PDUs) distribute power and protect IT loads running normally. Conversely, uninterruptible power supplies (UPSs) ensure there is enough power, at least for a short time, to run your equipment until you can find another available power supply (i., a. PDU (Power Distribution Unit) and UPS (Uninterruptible Power Supply) are both essential components in ensuring reliable power distribution and backup in data centers and other critical infrastructure. How it Works: A UPS contains a battery (or battery bank) and inverter circuitry.