Mini-LED refers to the backlight of an LCD television, not the display layer that produces colour. It uses LEDs that are far smaller than those in older backlights, which means many thousands of them can be packed behind the screen and grouped into hundreds of individually controlled dimming zones.
For viewers, more dimming zones translate into more precise control over which parts of the picture are bright and which stay dark at the same time, reducing the halo like glow that can appear around bright objects on darker backgrounds with older backlight designs. Mini-LED sets can also reach very high peak brightness, which helps with HDR highlights and viewing in a sunlit room.
Mini-LED is a backlight technology, so it is often paired with a quantum dot colour layer under names like QLED, and it remains an LCD design rather than a self emissive one like OLED, which affects how it handles very dark scenes. See our guide to TVs for bright rooms for how this plays out in practice.
