A payment gateway is a technical intermediary that passes transaction data between the merchant site, banks and payment systems. It accepts the details, encrypts them, sends the charge request and returns the payment status to the store.
What the gateway does
- Accepts card details on its own secure page rather than on the merchant site.
- Runs the operation through anti-fraud and triggers 3-D Secure confirmation.
- Returns the result to the store and sends a notification to its server.
How it differs from an aggregator
- The gateway is the technical part: the data channel and the processing of an operation.
- The aggregator is the commercial one: the contract, the set of methods and settlement.
- In practice one service usually provides both, so the words are often used as synonyms.
How a payment aggregator differs from a bank is covered separately.
