Is xdz the same as dzx?

I have noticed that sometimes professor Ng writes dw = xdz and other times dw = dzx. From my understanding, when dealing with matrices, the order of operands matters. This is confusing me as I had at first understood it to always be dw = xdz. Please make this clear to me

When I do computations,I see x as a cofficient.
For example, I can write d(2x) as 2dx
And x here is constant in this progress,so x can be seen as a cofficient.
So xdz=dzx