What kind of cards do they mean?

Credit/Debit cards are owned by certain companies which distribute it to various banks.

Major card companies are VISA card and MASTER card. When they distribute it to the bank, if we chose money to be deducted from our saving accounts rather than taking it on loan from bank, it's called Debit Card.

If bank lends us money and we pay to the bank later on, it's called Credit card.

I think so. I have a debit visa and it works for pretty much everything that requires a credit card.

I doubt …. Since It says credit card only … yours is debit card …

I’d ask them tho …

Yes. Mastercard is your Debit Mastercard they are just too lazy to write the full name out.

Source: Shopaholic with mastercard 💳

you already paid,

credit cards are where u pay later and most machines take both, whether they say so or not

I don’t know what a debit MasterCard is. Could it be a prepaid credit card?

Yes

Debit and credit cards are different cards even though they can both be owned/manufactured by Visa and or MasterCard.
A debit card is tied to an account that has money already in it and it withdrawal from that money. A credit card is buying on credit and paying the bill in the future.
But if this says credit card only it might not work with debit. Sometimes it will but it really just depends on the situation.