What Is Liquid Crystal Display (LCD)?

LCD (Liquid Crystal Display) is a flat, thin display technology that has largely replaced CRT monitors. It offers better image quality and supports higher resolutions.
While commonly used in monitors, LCDs also power screens in laptops, calculators, cameras, watches, and similar devices.

How Do LCD Screens Work?
LCD screens use liquid crystals—materials between a solid and liquid—to control light passing through each pixel. When an electric current is applied, the crystals align to block or allow light, similar to opening or closing a window shutter. A backlight shines through the screen, and each pixel (made of red, green, and blue filters) is controlled by the liquid crystals to display specific colors or remain dark. Unlike CRTs, LCDs don’t emit light themselves—they manage light from the backlight, making them more energy-efficient.

LCD vs LED: What’s the Difference?
LED (Light-Emitting Diode) screens are actually a type of LCD display and the key difference is the backlighting technology.
– LCD screens use CCFL (cold cathode fluorescent lamps) for backlighting, which provide uniform light but struggle to show deep blacks.
– LED screens use LEDs for backlighting, offering better energy efficiency and improved contrast, especially in dark scenes.

For example, in a dark movie scene, LED-backlit LCDs can light only specific areas (like a crack of light under a door), while keeping the rest of the screen dark—something CCFL-backlit LCDs can’t do as well. However, only some LED displays (usually full-array types) support local dimming for enhanced black levels—edge-lit LED screens generally don’t perform as well in this area.

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