px

Pixel

The smallest unit of measurement in digital imaging and web design. On a physical display, each pixel represents a single point of light composed of tiny light-emitting diodes (LEDs) or liquid crystal cells, depending on the type of screen. These pixels combine to create images and text on digital displays such as monitors, TVs, and smartphones.

Physically, a single pixel comprises three subpixels—one red, one green, and one blue (RGB). By adjusting the intensity of each subpixel, the pixel can display a wide range of colors. On LED displays, each subpixel is an individual LED that emits light, while on LCDs, each subpixel filters light from a backlight.

Pixels are not a fixed physical size and vary based on the device’s screen resolution and pixel density. For example, high-resolution screens have more pixels per inch (PPI), resulting in smaller, more densely packed pixels that produce sharper, more detailed images.

In web design and CSS, the pixel is a common unit used to define the size of elements like fonts, images, and layout dimensions. While 1 px is roughly equal to 1/96th of an inch based on industry standards, its actual physical size will vary depending on the display’s pixel density and resolution.

• Abbreviation: px