The word "voxel" comes from the phrase "volumetric element," which is basically the 3D analog to 2D pixels. Voxels divide 3D space into uniform 3D cubes — think of Minecraft-style look (although the game doesn't actually use voxel rendering as it's still very resource-intensive). If polygonal models are like meshes, voxels are similar to clay because they have volume, which is great to represent non-homogeneously filled spaces. Voxels are widely used in volumetric imaging in medicine and representations of terrain in games and simulations.^[1]