Matrices of any order can be added.

Matrices of different order cannot be subtracted.

Matrix addition is associative as well as commutative.

Matrix multiplication is commutative.

A square matrix where every element is unity is called an identity matrix.

If $A$ and $B$ are two square matrices of the same order, then  $A+B=B+A$.

If $A$ and $B$ are two matrices of the same order, then$A-B=B-A$.