What is the difference between a debit and prepaid card?

You are correct in that they are one and the same.

It is correct to assume that a fully re-loadable prepaid product (linked to a prepaid account) is the same as a debit card, as it can only be used when the cash is there. Other "limited function" prepaid cards like Gift Cards (typically not re-loadable) are like debit cards in that once they are used up, they are useless (unless they can be re-loaded).

What is not being stressed enough is that BANKS NO LONGER WILL PREVENT DEBIT CARDS FROM OVERDRAWING ACCOUNTS Unless you are aware of your exact account balance each day you may accidently overdraw your account. Banks count on this because current OverDraft fees are 31 to 34 dollars. In fact Banks make Billions of dollars each year on overdraft fees. There is a bill currently under review that would force banks to cease this predatory practice. A couple of years ago my bank would not allow a debit card charge if there wasn't sufficient funds. With out any notice my bank changed the policy and I was shopping one day and bought several items. At the same time my wife went shopping with her sister and bought several items. Neither of us had a problem. Since we were buying Christmas presents we didn't exactly talk about what we bought. We ended up with $340 in overdraft fees. to quote Elmer Fudd "Be vewy vewy caweful"