A power inverter is an electronic device witch transforms the current from DC to AC and from a lower voltage to a higher voltage. E.g. 12v DC to 240v AC, 12v DC to 110v AC, 24v DC to 220v AC...etc
A power inverter has an input and one or multiple outputs. To their input is generally connected a battery or a battery bank and their outputs are just like a regular house power point where you can connect almost any electronic device that requires to be plugged into a power point, we're talking about a medium to a large capacity inverter. E.g.: TV, radio, lamp, vacuum cleaner, toaster, hair dryer, power drill, electric saw... depending on the size of your inverter which can vary from a few watts to a few KWs output.
There are two types of power inverters: modified sine or pure sine.