If you are at all familiar with displays, from laptop computers to digital watches, you have most likely come into contact with the LCD, short for liquid crystal display. LCD screens and LCD technologies have risen in prominence over the past few decades, especially overtaking the previously popular cathode ray tube (CRT), as the intricacies beneath the surface of the display have advanced in quality and efficiency.

LCD (Liquid Crystal Display) technology works by controlling the passage of light through a liquid crystal layer sandwiched between two polarized glass panels. Here's a simplified explanation of how LCD works:

1. Liquid Crystals: Liquid crystals are substances that have properties of both liquids and crystals. They can flow like liquids but have molecular structures that resemble crystals. In an LCD, the liquid crystals are typically made of rod-shaped molecules.

2. Polarization: The glass panels in an LCD have polarizing filters that allow light waves oscillating in a specific direction to pass through. The filters are perpendicular to each other, so when no voltage is applied, the liquid crystals align in such a way that they twist the polarized light.

3. Alignment: The liquid crystal layer is sandwiched between electrodes on the glass panels. These electrodes apply an electric field to the liquid crystals, causing them to realign their molecules. When voltage is applied, the liquid crystals untwist and align with the electric field.

4. Light Modulation: As the liquid crystals align or untwist, they act as a light valve, modifying the passage of light through the pixel. When the liquid crystals align to allow light through, the pixel appears transparent. When they untwist to block the light, the pixel appears opaque.

5. Color Filters: To generate colors, LCDs use color filters placed in front of each pixel. These filters divide the white light into red, green, and blue components. By adjusting the intensity of light passing through each color filter, a wide range of colors can be produced.

6. Backlighting: LCD panels require a backlight source to illuminate the pixels. Older LCD displays used CCFL (cold cathode fluorescent lamps), while modern displays use LED (Light-Emitting Diode) backlighting. The backlight is positioned behind the screen, and its intensity can be controlled to adjust overall brightness.

7. Image Formation: By precisely controlling the alignment of liquid crystals for each pixel, the LCD creates an image on the screen. The combination of millions of pixels arranged in a grid forms the complete picture.

It's important to note that newer display technologies such as OLED (Organic Light-Emitting Diode) operate differently and do not require a backlight. Instead, each pixel emits its own light in OLED displays, resulting in improved contrast and viewing angles compared to LCD technology.