An order set of n numbers is called an n vector or a vector of order n . X which is an order set of n number x1, x2 ,x3 ...... , xn can be written in two forms.

The vector x in the first form is known as row vector and vector x in the second form is known as column vector .

The numbers x1, x2 ,x3 ...... , xn are called the components of the vector X .