AB can be written as the sum of the outer products of column i of A with row i of B. The keyword here is the outer products. *xᵀy *is different from *xyᵀ*. This is another perspective of describing the same thing. Here is how it may be used from this perspective.

https://www.quora.com/What-is-an-intuitive-understanding-of-the-outer-product-of-two-vectors