A pixel is the smallest unit of a digital image. The word comes from picture element. A pixel is a tiny square of color. When millions of pixels are arranged in a grid, they form an image. The more pixels, the more detail the image can hold. A 24-megapixel image contains 24 million pixels. Each pixel has a color and brightness value. In a standard RGB image, each pixel has three values: one for red, one for green, and one for blue. The combination of these values produces the full range of colors.

Pixels are not just for images. They are used in displays, where each pixel is a tiny light-emitting element. A 4K display has about 8 million pixels. A 1080p display has about 2 million. The pixel density of a display is measured in pixels per inch. Higher density means sharper text and images. Pixels are also used in printing. A print resolution of 300 pixels per inch is considered high quality. Below that, the individual pixels become visible. Pixels are the building blocks of digital images. They are invisible individually, but together they create everything we see on a screen or a print.

Pixel facts

• Definition. Picture element, the smallest unit of a digital image.
• RGB. Each pixel has red, green, and blue values.
• Resolution. Measured in pixels, width by height.
• Density. Measured in pixels per inch.
• Print. 300 ppi is standard for high-quality prints.

A pixel is not the same as a dot. A dot is a unit of printing. A pixel is a unit of digital display or capture. The two are related but not identical.