Payment Integration also called "payment gateway" is a service provided to the website uesr to do the payment via credit card or bank transaction. The payment transaction happens between bank and the user through payment portal designed in the website.
Payment gateways are mandatory service these days for ecommmerce websites. The client who visits the ecommerce websites for buying the product, would like to pay the merchant through online bank transactions. The credit or debit card and other facilities bank provides can be used to make the transaction.
Transactions made by the customers to the merchants are recorded and it is customizied to view, print or download them. The facilities are provided through payment gateway reporting features.