voxel
A cube of volume in a three-dimensional grid, the 3D equivalent of a pixel, and the building block of blocky games and many medical scans.
A pixel is a coloured square in a flat picture. A voxel is the same idea with a third dimension added: a small cube sitting at a fixed position in a 3D grid. Stack enough of them and you can describe any solid shape, which is why voxels turn up in two very different places, blocky sandbox games and medical imaging, where a CT or MRI scan is essentially a stack of voxels.
In AI the term appears whenever a system has to reason about volume rather than a flat image, for example in robotics, 3D generation or scan analysis. It also appears in copyright arguments, since the visual style of cube-based games has been the subject of repeated takedown disputes. A cube grid is a technique, not something anyone can own.