Ever been confused what happens when an online payment goes through a website? Checkout Merchants created this easy to follow process flow that shows you the flow of web payment. it clearly shows you the link between a merchant account and what is a payment gateway. See how a transaction goes from the buy now button to the authorization of the credit card. CLICK on the image to enlarge. you are not the only one that has been confused by accepting card payments online. This 9 step flow will take you through the web payment process . What the heck is a payment gateway and merchant account? See how it works.