From 2D to 3D

Moving from 2D (two-dimensional) to 3D (three-dimensional), we move from pixels (picture elements) to voxels (volume elements). Pixels are more commonly known than voxels. Voxels are just the 3D counterpart of pixels, which are 2D. A 2D image is composed of many tiny squares. A 3D volume of images is composed of many tiny cubes. In 2D, we have one dimension for width, another dimension for height. In 3D, we get an additional measurement: depth.