A rectangular array of numbers arranged in horizontal and vertical enclosed between round (or square) brackets is called a matrix. Matrix: Arrangement of numbers vertically or horizontally. Matrix A rectangular array of numbers arranged in horizontal and vertical enclosed between round (or square) brackets is called the matrix. Horizontal lines are called rows and vertical lines are called column of the matrix.

If A and B are two matrices of the same order, then A and B are said to be Conformable or Compatible for addition. If A and B are two matrices of the same order, then they are said to be conformable for subtraction. If A is any matrix and K is any constant or a scalar, then the matrix obtained by multiplying each element of A by K is denoted by KA and it is called the scalar multiple of A by K.