What do inverter & UPS do, and what can I use them for?

The full name of UPS is uninterruptible power supply. Inverter & UPS can charge batteries when utility power is normal and transfer DC power from batteries into conventional AC power immediately when utility power is failed or abnormal. You just need to connect inverter or UPS to batteries and plug your AC devices into inverter or UPS, then you can operate all kinds of device as usual. You can get a portable power whenever and wherever you need.