An e-commerce application service provider that authorizes credit card payments for a business.
It is the equivalent of a physical POS terminal located in most physical retail outlets. Payment gateways protect credit card details by encrypting sensitive information, such as credit card numbers, to ensure that information is passed securely between the customer and the merchant and also between merchant and the merchant processor.
A payment gateway facilitates the transfer of information between a payment portal (such as a website or tour operator software) and the merchant processor or bank.
In order to accept credit card payments online, a business must have both a merchant process (who processes the payment) and a payment gateway (connects the business website to the merchant processor). In some cases, eg. Stripe, Authorize.net, or PayPal, the payment gateway and the merchant processor are the same.
More information about payments can be found here: Payments
Find a list of leading payment gateways here: Payment Gateways