All LCD monitors have backlight, otherwise you will not be able to see the images on the screen.
Currently there are monitors with CCFL (florescent) backlight and LED backlight (which is newer). Higher contrast ratio doesn't always mean better picture and there are two types of contrast ratios. Static contrast ratio is the older and truer method; most TN and IPS panel monitors have up to 1000:1 static contrast ratios, while PVA panel monitors can have up to 4000:1. Generally speaking, the higher the contrast ratio, the darker black will be compared to other colors.
Dynamic contrast ratio is the newer method and also very misleading since the ratios tends to be advertised as much as 2,000,000:1. What basically happens is that the backlight's brightness automatically adjusts itself based on what appears on the screen. The darker the color tones, the dimmer the backlight will be. The brighter the colors, the brighter the backlight will be. I personally find dynamic contrast annoying so I switch it off on my HDTV and my Asus 24" VK246H monitor (my other monitors don't have it).
For more info about LCD tech read the following:
http://www.tftcentral.co.uk/specs.htm