Zimba wrote: Wed 20 Mar, 2024 18.48
Debit cards can be used offline.
Not universally. Online only debit cards, which may or may not be branded differently from offline-enabled debit cards, are a thing, and have been since Visa retired the Electron brand in the UK (at least).
When they first moved to Visa from Solo/Maestro Natwest and RBS issued different designs to represent the online-only ones (replacing Solo) and the offline enabled ones (replacing Maestro) - but neither had wording to suggest there was or wasn't a limitation and both had embossed numerals (implying an old fashioned impression could be taken). I remember some railway TVMs had staff created signs advising 'blue Natwest Visa cards wont work in this machine' and similar.
By contrast Santander replaced their Abbey Electron cards with Visa Debit cards which were essentially the same as before - flat card with the clear 'electronic use only' wordage as common on Electrons.
Subsequently all the above were replaced with designs which were the same* for both online and offline cards. In fact, I think it's possible for a card's offline ability to be swapped 'on the fly'.
*save for a few oddities - like if you get an RBS account at the "London Child & Co" branch you'll get a fancy Child & Co card, except if RBS opt to give you an online-only card, in which case you'll get the default RBS design.