What is an inverter?

What is an inverter?
Inverter is a device that converts DC voltage to AC voltage. In most cases, the input DC voltage is usually low, while the output AC voltage is equal to either 120 or 240 volts of grid supply voltage, depending on the country/region.
Inverters can be built as standalone devices for applications such as solar power, or as a backup power source for batteries that are charged separately. Another configuration is when
When it is part of a larger circuit, such as a power supply unit or UPS. In this case, the inverter's input DC comes from the rectifying mains AC in the PSU, from the rectifying AC in the UPS when power is available, and from the battery when the power fails.