In: Physics
We can see in the card that it has a black strip which is made up of magnetic material. This material contains a lot of information on it which is stored as the orientation of the magnetic particles on it. When card is read in a machine it send a lot of information to the bank and bank received that info and then it asks for the validation of the payment. Then we can enter the pin set up by the card user. After authentication the payment is success ful.