There are several categories of discount rates based on how the transaction is processed:

Card-Present, or “Swiped,” Transactions

A swiped-transaction occurs when the merchant “swipes” the credit card through a terminal or card reader and has the lowest discount rates.

Card-Not-Present Transactions

Card-not-present transactions occur when the merchant does not physically “swipe” the customer’s card. There are two forms of card-not-present transactions:
Keyed-transactions where the merchant “manually” keys-in the card number (e.g. mail order and telephone order)
Internet transactions

These types of transactions have higher discount rate charges since the credit card is not present and the consumer does not sign a sales receipt.