A pixel, short for “picture element,” is the smallest unit of a digital image or display that can be individually manipulated. It is a single point in a raster image and serves as the basic building block of digital graphics.
Pixels are arranged in a grid to form an image on a display screen. Each pixel can display a color, which is typically represented by a combination of red, green, and blue (RGB) values. The resolution of an image or screen is determined by the number of pixels it contains, usually expressed as width × height (e.g., 1920 × 1080).
In web development, pixels are often used as a unit of measurement for defining dimensions and positioning of elements in CSS.