The contrast ratio on your television measures the difference between the brightest and darkest colors your TV can display. The higher the contrast ratio, the deeper the blacks and the brighter the whites.
TV manufacturers love to promote their ultra-high contrast ratios. But the dirty little secret of the TV world is that dynamic contrast ratio is irrelevant. All it measures is how your TV uses backlighting to brighten or dim a picture.
"Native contrast ratio," which measures the blacks and whites on a single, standard-lit picture, is the number to care about!
Still, there is no standardized, reliable way to measure contrast ratio. That means every contrast figure that TV manufacturers put on their boxes -- including the native contrast ratio -- uses different testing criteria.
That has also led to some outlandish contrast ratios that could never be proven. Some TVs on the market seriously claim to have a 1,000,000,000,000,000,000,000,000,000,000,000:1 contrast ratio. Get real.