# Matrix Multiplication (행렬의 곱)

Matrix Multiplication
The matrix multiplication is a binary operation that takes a pair of matrices, and produces another matrix. If $A$ is an $n$-by-$m$ matrix and $B$ is an $m$-by-$p$ matrix, the result $AB$ of their multiplication is an $n$-by-$p$ matrix defined only if the number of columns $m$ of the left matrix $A$ is the equal to the number of rows of the right matrix $B$.
In general, matrix multiplication is not commutative. More precisely, $AB$ and $BA$ need not be simultaneously defined.