Voxels are discrete, so not absolutely tiny. Voxel = vox (volume) + el (element), similar to pixel = pix (picture) + el. Do you know Minecraft? All those cubes

Voxels are discrete, so not absolutely tiny. Voxel = vox (volume) + el (element), similar to pixel = pix (picture) + el. Do you know Minecraft? All those cubes in its world are voxels. The amazing thing here is how tiny this guy's voxels are while still keeping the game running at a decent framerate. Compared to traditional polygon graphics: voxels are discrete elements in space (sort of like "giant atoms") while polygons are the surface of objects (cuts of planes in 3d space). Being merely polygons they have no depth (as GP said, they're paper-thin) while voxels are inherently volumes in your space. You could compare it to Lego vs. papercraft.