What is the difference between and LCD, an LED and a combo LCD-LED TV screen?

You are confused because TV makers are using their marketing to confuse you. So first thing, there is no such thing as an "LED" TV. All these TVs are just LCD TVs. A LCD TV uses a CCFL backlight to create the light. LED TVs replace that backlight with LEDs. That's all. The pixels in LCD TVs don't create their own light the way plasma pixels do. Technically, you could use anything that creates light for a backlight. It could be a lightbulb, LED, or candles, fire you name it. Changing the backlight does not give you better image quality, deeper blacks, higher contrast or anything else. LEDs can give you a slightly brighter image, and has the possibility to show a wider color gamut but most people will never notice it. In cases where you have a LCD TV sitting next to an LED TV and the LED looks better, well it has nothing to do with the LEDs. Two reasons for the difference in image quality are 1. TV makers tend to use superior glossy screens with higher end LED TVs, and 2. They are usually a newer, or later generation panel. So those LCD TVs might be using a 6th generation panel, and a "LED" might be using a 10th generation panel. That's where the extra contrast, and deeper blacks and better colors come from. So if an LCD TV seems to have image quality that is pleasing to you, and it has the features you want, and you can afford it, go for it. There is nothing magical about LED that's going to make things better. Now that LED is going down to cheaper TVs, they are losing the glossy screens and the newer generation panels, so unless it's a really high end set, going LED doesn't always mean better.

I am not a big expert on the subject but I can offer some help. LCD = liquid crystal display LED = light emitting diode . LCD tv's use florescent tubes as a back-light, and LED tv's do not need a florescent back-light. From what I understand they are able to make LED thinner because of this. As far a quality of the picture, I'm not sure there is any difference. LED is the new technology, so you might be able to grab an LCD as prices drop. Or even the DLP. DLP use projection light and be just as good. They are cheap right now.