Voltage inverter, backlight inverter.

The back lit screen is just this. It has screen film that is constantly changing color and brightness in thousands of pixels. But the screen does not light up we have to let the light pass thru the screen film so we can see all this magic.

This light comes from small long fluorescent tubes located around the sides of the screen. There can be two or more and like a household light it requires a voltage inverter to step up the voltage to fire up the tubes.

I have a feeling one of your tubes is faulty as in my experience one inverter can light two tubes. this means the bottom half light is working and the top light is not. If you have dropped your display it may have broken the tube or even severed the wires . Or I could be wrong and this display has two inverters one for each tube. Could be 4 tubes and you get the picture. You have to decide wither to take it apart and see what is going on inside and replace a faulty inverter or tube but for the age of the unit a shop price would out weigh the cost of a new one. Or a second hand one is another option.

Good luck

I would suggest if you buy another second hand will save you money and headache.

The simple answer for the question is

The voltage inverter and backlight inverter can be the same where and how the person described the item.

As for me, I call "Backlight driver" and the power supply or power control unit for the machine. So I would say it might be the same or different depend on how the person think.