Cartridges or optical discs?

[SvennoJ]

curl-6 said:

SvennoJ said:
CD / DVD / Blu-ray / UHD can all be read by the same reader, cartridges are not backwards compatible.

To be fair, can you pop a PS1/PS2/PS3 disc in a PS4 and play it?

You can pop a 360 disc in the one and play it, soon perhaps also certain original xbox discs.
You can pop ps1 and ps2 discs in an original ps3 and play it.
You can pop a GC disc in a Wii and play it.
You can pop a Wii disc in a WiiU and play it.

You will never be able to pop a disc in the Switch, nor a 3ds cartridge btw.