Cameras with more dynamic range allow you to take photos with dramatic differences in highlight and shadow areas while retaining detail in both.
Think of a brilliant sunset on a rocky beach: Bright sunset in the background, with dark rocks in the foreground. High dynamic range means more of the extremes will be faithfully reproduced.
Dynamic range test data courtesy of DxO Mark.D750 test data on DxO Mark 6D Mark II test data on DxO Mark
Outstanding image quality with great dynamic range and high ISO performance; Class-leading burst rate; Very good 51-pt AF system; AF system works in very low light; Deep, comfortable handgrip; Articulated LCD monitor; Excellent battery life; Uncompressed 4:2:2 HDMI video output; Built-in Wi-Fi.
Buffer fills quickly with 14-bit RAW; Sluggish Live View AF; Shutter speed tops out at 1/4000s; OVF coverage closer to 97%; Weak low-pass filter is great for detail but higher risk of moire.
Great vari-angle touchscreen; Dual Pixel CMOS AF; Good image quality in most situations; Impressive performance for its class.
Disappointing dynamic range; No 4K video; Optical viewfinder comes up short; Narrow AF point coverage through viewfinder.