A payment gateway is a commercial service offered by an e-commerce application provider that allows e-business credit cards, online retailing, traditional brick, clicks, and mortar payment processing. A payment gateway may also be provided by banks to its customers and may be supplied by an independent specialist financial service provider such as PayPal, square, stripe, etc.
A payment gateway enables the exchange of payment information between the gateway and the front-end processor (such as a website, mobile phone, or interactive voice response system) or the acquiring bank.