>>717473362
Crudely put. It's a 3D Pixel.
But just think of it as block shaped building blocks. They come in all kinds of sizes depending on the project in question.

Also kind of related.
https://www.nintendo.com/us/whatsnew/ask-the-developer-vol-19-donkey-kong-bananza-part-2/
goes into more detail on how Bananza in particular uses voxels.