The smallest unit of a digital image, representing a single point of data.A pixel is the smallest addressable element in a digital image, a single point of data that, when combined with millions of others, forms a complete picture. Each pixel carries numerical information about color and brightness, typically represented as a combination of red, green, and blue intensities. The resolution of an image — its sharpness and detail — is determined by the number of pixels it contains, with more pixels allowing finer gradations of visual information.
The term 'pixel' was coined in 1965 by Fred C. Billingsley, an engineer at NASA's Jet Propulsion Laboratory, to describe the picture elements in television and digital images.
In a digital camera, light strikes a sensor made of millions of photodiodes, each converting photons into an electrical charge proportional to the light's intensity. This charge is then quantized into a digital value, often 8 or 12 bits per color channel. The resulting grid of numbers is what a computer stores and displays, with each pixel's color reproduced by tiny light emitters on a screen.
Pixels are fundamental to all digital imaging — from smartphone cameras and medical X-rays to satellite imagery and computer graphics, where every visual output is ultimately a grid of pixels.
A single 4K television screen contains over 8 million pixels, yet each one is so small that individual pixels are invisible to the naked eye at normal viewing distances.

