An inverter is an electronic device that takes a DC input and converts it into an AC output.
Since car batteries provide DC voltage, and most consumer electronics work on AC, inverters are useful for using laptops and other devices on the road.
However, there are some vital constraints to keep in mind whenever you use an inverter in your car.
Factors like the capacity of the car battery, rated output of the alternator, and output wattage of the inverter can all play a part in determining which devices can be plugged in and used.