Final answer:
Ray Kramer was authorizing and confirming the payment for the invoice when he initialled it, wrote the date, check #, and "Paid" at the top.
Step-by-step explanation:
When Ray Kramer initialled the invoice, wrote the date, check #, and "Paid" at the top, he was completing the process of authorizing and confirming the payment for the invoice. This action signifies that the invoice has been reviewed and approved for payment. The initials and date serve as a means of documenting and tracking who authorized the payment and when it was done.
A payment gateway is a merchant service provided by an e-commerce application service provider that authorizes credit card or direct payments processing for e-businesses, online retailers, bricks and clicks, or traditional brick and mortar.
The payment gateway may be provided by a bank to its customers, but can be provided by a specialised financial service provider as a separate service, such as a payment service provider.