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.D3300 test data on DxO Mark 5D test data on DxO Mark
Excellent image quality with lots of fine detail; Very good high ISO performance; Good dynamic range; Good print quality; Deep buffers with JPEGs; 1080/60p video; Uncompressed HDMI output.
AF struggles in low-light; Contrast-detect AF in live view is slow; Buffer depth is shallow with RAW files; No AE bracketing; No built-in Wi-Fi.