What is Payment gateway?
A payment gateway is the service that securely collects a customer's payment at checkout, authorises it with the bank, and passes the money to the merchant.
The gateway handles card and UPI processing, fraud checks and compliance, so the merchant never stores card details directly.
Gateways charge per transaction rather than a fixed monthly fee, typically a percentage plus tax. The effective rate depends on your method mix — a UPI-heavy business pays materially less than the headline card rate suggests.