Bare bones Credit Card processing workflow

Some of my recent work deals with accepting credit card and other form of cards and settling them.

I have had some challenges to understand some basic terminology itself so I thought that it would be good to share my summary with others, in case they need it.

So, here it is...

There are quite a few key players

1. Card Holder - person who has the card, say, VISA.
2. Issuing Bank - Bank which issued the card (VISA branded card) to me. Say, Bank of America
3. Merchant - let's say i want to buy something at www.amazon.com
4. Acquiring Bank - Amazon.com may have an account with some bank like Wells Fargo and as and when amazon gets the money paid by customers, it is deposited into its account with Wells Fargo bank.
5. Payment Processor - It can be someone like Chase Payment tech which accepts online payment requests from Amazon.com
6. Card Network - VISA/MasterCard/Amex have their own electronic network to accept the payment request and they route the request to Issuing Bank, for authorization.
7. Payment Service Provider - These are online players like Paypal and Amazon Payments who certify themselves as Merchants with Card Networks and act on behalf of small merchants. (sub_merchants)
8. Sub-Merchant - Small merchants who may not have the muscle/resources to go thru lengthy  + costly certification process with card networks and banks.
9. Payment Gateway - CCBill or other online services which deal with processors and banks.

There are 2 basic workflows

1. Authorize - when card needs to be authorized for the amount of sale requested
2. Settlement - When the amount of sale transaction  is deducted from Customer's account and deposited into Merchant's account 

Please note that these are simplified descriptions for ease of understanding.

Overall workflow can be visualized as depicted here and here