Commonwealth EFTPOS Keycard

'Keycard' is the brand name for Commonwealth Bank's EFTPOS Debit card. A debit card is just a card where your funds are used, as opposed to the banks funds (a credit card, where you pay later).

I think you mean the difference between a Keycard and Debit Mastercard.

A Keycard is used primarily for the EFTPOS network in Australia and at ATMs. You press SAV or CHQ to access your money. You can't use it online or over the phone. You can use it overseas where 'Maestro' or 'Cirrus' is displayed.

A Debit Mastercard is much more flexible. You can use it whereever credit cards are accepted, including in-store, over the phone, through the mail or on the internet. You also get access to PayPass, which allows contactless instant payments under $100 at participating stores. Most importantly, a Debit Mastercard is also an EFTPOS card. You can press CR (credit) as well as SAV or CHQ.