I don’t understand this new concept of postpaid. In the olden days, prepaid meant pay first and then use for the duration of the plan. And postpaid meant, use the mobile for the month and get the bill at the end of the month according to number of calls and amount of data used. Now, for both prepaid and postpaid, the payment has to be made upfront itself? Then why call the plan postpaid? What is the difference now between prepaid and postpaid?