cubes as matrices

Question

I've read on-line that there is some way, shape, or form to represent matrices as cubes, like maybe a $2\times 2\times 2$ matrix that you could use. how could you get a $2\times 2$ matrix $A$ into a $2\times 2\times 2$ matrix B? and then so on to $3\times 3\times 3$ matrix? and then could you compact it in the opposite way? and could you also determinate it and other things? thanks in advance.

Answer 1

I would argue that $B = (b_{ijk})$ might be a tensor, but is not a matrix.

A matrix has usually two indices, but not more.

Maybe you are taking arrays (data structures) for matrices (objects of linear algebra, having a well defined transformation behaviour).