Hii Nannu,

First of all Let me tell you two Concepts,

• Scalar quantity
• Vector quantity

A scalar quantity is nothing but a quantity which is defined by its magnitude or a numerical value.

Eg: Distance,time

A car travelling from Chennai to Mumbai takes 1500 km and same 1500 km for return journey.

 In this the Magnitude will not change with respect to direction.

Whereas a vector quantity has both magnitude and direction.

Eg: torque,momentum

So  Finally magnitude is nothing but a numerical value which is defined.

Thank you.