In 3D computer graphics, a voxel represents a value on a regular grid in three-dimensional space. As with pixels in a 2D bitmap, voxels themselves do not typically have their position explicitly encoded with their values. Instead, rendering systems infer the position of a voxel based upon its position relative to other voxels.
In computed tomography (abdominal CT pictured), voxels are generated by multiplying the field of view (FOV) by the scan range.
In digital imaging, a pixel, pel, or picture element is the smallest addressable element in a raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, pixels are the smallest element that can be manipulated through software.
A photograph of subpixel display elements on a laptop's LCD screen
Pixel art
Geometry of color elements of various CRT and LCD displays; phosphor dots in the color display of CRTs (top row) bear no relation to pixels or subpixels.
Samsung UA40M5860AKCHD TV subpixels