The concept

A payment gateway is the infrastructure that receives a transaction's data at checkout, sends it to the acquirer and the card network, and returns the approval or decline response. It's the technical layer between the moment the buyer clicks pay and the moment the money is actually moved.

Besides processing the charge, a full-featured gateway also covers fraud prevention, routing between acquirers, currency conversion, and the payout of the approved amount to the seller, net of fees.

How it shows up in practice

You're building a checkout and need to integrate card processing. A gateway receives the data securely, sends it to the network, waits for the approval response and returns whether the transaction went through. Without it, you can't process anything.

The simpler it is for the customer to understand the offer and move forward, the shorter the distance between interest and purchase.

Russell Brunson Source: concept developed in DotCom Secrets. Paraphrased by the editorial team.

A payment gateway is the technical infrastructure that moves the money. A complete gateway does more than just process: it does fraud prevention, converts currency, routes between acquirers and passes along the value after deducting fees. It's everything that happens between the buyer clicking pay and the money entering your account.