Outer Product

In linear algebra, the outer product of two coordinate vectors is the matrix whose entries are all the products of an element of the first vector with an element of the second vector, so that the outer product of vectors of dimension m and n is an m by n matrix. The concept extends more broadly to tensors, where it is also called the tensor product and helps define tensor algebra; it is distinct from the dot product, or inner product, which yields a scalar, from the Kronecker product, which yields a block matrix, from the Hadamard product, which multiplies entries element by element, and from ordinary matrix multiplication.