[Accacin]

So I've always seen the word "deck" and never really understood what it meant. Turns out a "deck" is just a powerpoint? Why do people call them decks?

[cvs268]

Physical slides were using transparencies or slides. A bunch of them stacked together would be like a deck of cards - a slide-deck.

[bloemy]

From "slide deck", which itself comes from "card deck", I'd guess.