Voxel

A voxel stores a value — occupancy, density, colour, material — at a cell in space, and a volume is a 3D array of them. Unlike a polygon mesh, which only describes the surface, a voxel grid also describes the interior. That makes the format natural for destructible terrain, for CT and MRI slices in medicine, and for fluid simulation, where you need to know what is inside and not merely where the shell runs.

The word was coined in the early days of volume visualization, through the 1970s and 80s. Games render voxels either by building a mesh from them — with greedy meshing for hard blocks or marching cubes for smooth surfaces — or by ray-marching the grid directly. Minecraft (blocks) and Teardown (destruction) are the best-known examples; see also voxel landscape and voxel art.