Payment terminal in the context of "Visa Inc."

The point of sale (POS) or point of purchase (POP) is the time and place at which a retail transaction is completed. At the point of sale, the merchant calculates the amount owed by the customer, indicates that amount, may prepare an invoice for the customer (which may be a cash register printout), and indicates the options for the customer to make payment. It is also the point at which a customer makes a payment to the merchant in exchange for goods or after provision of a service. After receiving payment, the merchant may issue a receipt, as proof of transaction, which is usually printed but can also be dispensed with or sent electronically.

To calculate the amount owed by a customer, the merchant may use various devices such as weighing scales, barcode scanners, and cash registers (or the more advanced "POS cash registers", which are sometimes also called "POS systems"). To make a payment, payment terminals, touch screens, and other hardware and software options are available.

A bank card is typically a plastic card issued by a bank to its clients that performs one or more of a number of services that relate to giving the client access to a bank account.

Physically, a bank card will usually have the client's name, the issuer's name, and a unique card number printed on it. It will have a magnetic strip on the back enabling various machines to read and access information. Depending on the issuing bank and the preferences of the client, this may allow the card to be used as an ATM card, enabling transactions at automated teller machines; or as a debit card, linked to the client's bank account and able to be used for making purchases at the point of sale with a bank card using a payment terminal. Later, in 2010s, smart card technology was adopted for bank card.

Payment cards are part of a payment system issued by financial institutions, such as a bank, to a customer that enables its owner (the cardholder) to access the funds in the customer's designated bank accounts, or through a credit account and make payments by electronic transfer with a payment terminal and access automated teller machines (ATMs). Such cards are known by a variety of names, including bank cards, ATM cards, client cards, key cards or cash cards.

There are a number of types of payment cards, the most common being credit cards, debit cards, charge cards, and prepaid cards. Most commonly, a payment card is electronically linked to an account or accounts belonging to the cardholder. These accounts may be deposit accounts or loan or credit accounts, and the card is a means of authenticating the cardholder. However, stored-value cards store money on the card itself and are not necessarily linked to an account at a financial institution. The largest global card payment organizations are: UnionPay, Visa, Mastercard and American Express.