The answer here uses the design of the payment part of the merchant's business system as an example to explain the concept of a gateway.

1. Definition of payment gateway

When it comes to payment gateways, you first need to understand the definition of a gateway. The function of the gateway is to realize the communication link between the Internet, payment gateway system architecture，including the two basic functions of Internet connection and protocol conversion. Similarly, the payment part in the merchant business system realizes the connection between the merchant business system and the bank payment system, plays a similar role, and can be regarded as a gateway. Therefore, the design of the payment gateway we are going to talk about today is actually the design of the payment module of the merchant business system.

2. The origin of payment gateway

In the era when electronic payment is not popular, merchants support the bank by connecting with the system interface provided by the bank. Then, as the payments industry continues to grow, merchants are no longer content to support just one or two banks in the payment process. At this time, the merchant's payment system needs to connect to multiple banks at the same time to deal with many derivative issues, such as account reconciliation and settlement. Furthermore, the labor cost and time required to develop such a system is unacceptable for merchants.

At this time, third-party payment institutions were born. They will develop and operate a system to replace merchants to realize the function of connecting with multiple banking systems at the same time, and then provide them to merchants through a unified interface. Therefore, the third-party payment institution system at this stage is the payment portal.

In addition to realizing the link between the merchant business system and the banking system, the basic functions of the payment gateway also include many other basic functions related to the payment business, including: order management, channel management, risk control management, routing configuration, account management, clearing management, Merchant management and user management, etc.

With the further development of online payment, there are more and more third-party payment institutions. The problem for merchants to solve is no longer how to access multiple banks, but how to access multiple payment institutions. At this time, the merchant's demand for the payment system has also changed, and the location of the gateway has also been further advanced, putting forward higher requirements for the merchant's payment system.

From the merchant's point of view, the main difference between the payment security gateway and the traditional enterprise payment gateway at this time is that the focus will be less, and the merchant only needs to pay attention to customer orders, channels, risk control, accounting information management and routing configuration issues.