I think the cassette is the thing that holds the media, as opposed to a reel-to-reel tape, which is just on a spool, for example. To this reading, it makes sens

I think the cassette is the thing that holds the media, as opposed to a reel-to-reel tape, which is just on a spool, for example. To this reading, it makes sense to call the game cartridge a cassette, but I haven’t ever heard of carts called cassettes in English.