Commodore has set up a microsite to help steer you towards its unique vision of a modern operating system. If you head over to commodore.net/closewindows, you will first see a banner image of the Commodore 64X PC with OS Vision. But that is essentially an x86 PC in a C64-style ‘bread bin’ chassis, so don’t worry about the hardware.
The c64 actually did have game cartridges, but be it tape, cartridge, floppy, cd - in the emulation space, ROM (Read-Only Memory) just generally means the file with the game data no matter the medium.
But technically, it’s a ROM only if it truly is a dump of an actual ROM chip.