Why do you need to choose (or tell the worker) “credit” or “debit” when paying for something by card? Are the two cards built differently?

Question

Why do you need to choose (or tell the worker) “credit” or “debit” when paying for something by card? Are the two cards built differently?

In: Other

Answer 1

Debit – instantly removed from your bank account. Credit – charged on card that is then going to charge you; during that period you get credited by the card that is paying on your behalf.