A card with traits from both ATM cards and credit cards (usually VISA or MasterCard). Banks issue this type of card either instead of or in addition to an ATM card. The card can be used anywhere the VISA or MasterCard logo is displayed, but a line of credit is not accessed -- the customer's chequing account is debited. It is "offline" because the account is not directly accessed -- there is a delay of 24 to 72 hours before the debit is made in the account. If you sign a slip of paper to complete the transaction, it is offline. In the Canada, a Personal Identification Number (PIN) may be required to use an offline debit card.
An offline credit card shares traits of both ATM and credit cards. Offline debit cards have the VISA or MasterCard logo on them and can be issued by a bank, instead of, or in addition to, an ATM card. They can be used at any establishment that displays the VISA or MasterCard logo, but using them does not access a line of credit -- it debits a customer's checking account, but there's a delay of 24 to 72 hours before the debit is made in the account.
This is when a debit card is processed as a credit card and the Merchant's terminal reads the card, identifies it as a debit card, and creates a debit against your bank account. However, instead of debiting your account immediately like a transaction that you enter your PIN it stores the debit for processing later, usually within 2-3 days.