So the PS3 doesn't read various formats of "discs" and CDs, DVDs and BluRays are all something different?
All of the things the PS3 reads have "disc" in the name of them.
Compact Disc, Digital Video Disc, BluRay Disc, and they all fit in the same slot.
With the master system example. Carts go in the cart slot, cards go in the card slot.
Does your PS3 have a new opening for each disc? No.
No, but that's my point, they are all
types of discs. Gamecube discs are tiny as well, but they're still a
type of disc. The 32X accepts different
types of carts through the same slot like the PS3. The DS has(had) two different cart slots, for two different
types of carts, just like the SMS.
The overall method that "discs" interact with hardware is the same.
The overall method that "cards" and "carts" interact with hardware is the same.
The overall method that "digital downloads interact" with hardware is the same.
The overall method that "cassette tapes" interact with hardware is the same.
The overall method that "disks" interact with hardware is the same.
SMS/SG-1000/Mark III card games coexisted with standard cart games. They had to call them
something to indicate the difference. Especially since they were asking the consumer to buy an add-on to run them. Same with the MSX. They couldn't just call them "Wimpy Carts", there had to be some sort of marketing to sell them.
Famicom carts say that they're "Cassettes". NES carts say that they are "Paks". It doesn't matter what kind of marketing term they're presented with, they're still types of cartridge games.
Anyway, cartridges are just cards shoved in a plastic shell. They're pussy versions of HuCards. They need big protective shells when all the HuCard needs is sleek plastic.
Obviously.