The Point of sale (POS) or Point of purchase (POP) is the time and place where retail transaction is completed. At the point of sale, the merchant will calculate the amount owed by the customer and indicate the amount, and may prepare an invoice for the customer, and indicates the option for the customers to make payment. It is also the point at which a customer makes a payment to the merchant in exchanges for goods or after provision of a service. After receiving payment, the merchant may issue a receipt for the transaction, which is usually printed, but is increasingly being dispensed with or sent electronically.
To calculate the amount owed by a customer, the merchant may use any of a variety of aids available, such as weighing scales, barcode scanners, and cash registers. To make a payment, touch screens, and variety of other hardware and software options are available.