A payment gateway is the service that processes credit card transactions for you when your customers are purchasing from your online store. The user fills out the secure online form with their credit card number and shipping / billing information. The Online store sends the credit card information to your payment gateway to authorize the transaction and process the payment. The gateway checks to see if the card is stolen or expired among other security checks. If the credit card information submitted to the payment gateway matches the information on file with the credit card company and the charge is approved the payment gateway will then transfer the money from your customers credit card into your merchant account.
Velocity Webworks has integrated with the following payment gateways : Authorize.net, Elavon, Protect Pay and PxPay.
A merchant account is essentially an online bank account that temporarily holds the merchants money until it is moved to the bank account. After a successful sale, funds will be transferred into your merchant account and it will sit there between 1 and 3 days then it will automatically be transferred into your bank account.