In the past embossed credit and debit cards were both accepted on planes. That's why they were embossed in the first place: for offline processing which in even more distant path was the only option. Later CC machines and offline chip/stripe transactions co-existed with online transactions.
Normally (at least in Europe) you couldn't get an embossed card, even a debit one, without proving your credit worthiness. The possibility of offline transactions assumes overdraft — the same as with check books.
When online transactions appeared, banks started to issue Visa Electron and Maestro cards which didn't work offline, could explicitly prohibit overdraft and were easier to get.
But nowadays all boundaries gradually disappeared. Nothing is embossed, Visa Electron doesn't exist, bank issue debit cards with credit codes. It's all much simpler and more confusing at the same time.
Ironically, the few embossed cards I still have are from debit or prepaid issuers, presumably in a plot to make them look more "official", so at this point we've looped around completely and I've started associating it with a dated/tacky look. (They also take up twice the space in my card wallet and often lose their cheap metallic paint over time, annoyingly spreading glitter across my pockets.)
In the past embossed credit and debit cards were both accepted on planes. That's why they were embossed in the first place: for offline processing which in even more distant path was the only option. Later CC machines and offline chip/stripe transactions co-existed with online transactions.
Normally (at least in Europe) you couldn't get an embossed card, even a debit one, without proving your credit worthiness. The possibility of offline transactions assumes overdraft — the same as with check books.
When online transactions appeared, banks started to issue Visa Electron and Maestro cards which didn't work offline, could explicitly prohibit overdraft and were easier to get.
But nowadays all boundaries gradually disappeared. Nothing is embossed, Visa Electron doesn't exist, bank issue debit cards with credit codes. It's all much simpler and more confusing at the same time.