OLED: Contrast and black levels. Though some high-end QLEDs can get close, OLED TVs are still the kings of contrast and black levels, no matter which model you buy.

QLED is their premium, higher-quality range, and Crystal UHD is their cheaper range, which is reflected in their price. With a QLED television, you'll have a wider range of colour (including its dynamic range), more brightness, and improved contrast, among other benefits.

The Samsung Q70/Q70A QLED is better overall than the Samsung Q60B QLED. The Q70A has more gaming features like HDMI 2.1 bandwidth, a 120Hz panel, and VRR support, all of which the Q60B doesn't have. Also, the Q70A has a much better response time for better motion handling.

A UHD TV operates like a QLED TV in that it has an LED backlight and LCD screen, but it lacks the QLED TV's quantum dots used to improve color and brightness. The most important thing to remember is that UHD is not technically a type of TV, but rather a description of its 4K resolution.