system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is a game converted to a rom for emulation purposes?

I'll just ask about Dolphin's Game Cube since I use it. How does the rom process work in allowing a GC game to be played on Android?

Does the process have anything to do with why there are only a limited number of roms?
gpt
A rom is just a copy of the media.  In case of GC it's a copy of the data stored on the CD.  Some roms are encrypted, like on the 3ds and you need to decrypt them before use on a device.

They're called ROMs because originally they were the *dumps* of Read Only Memory chips found in cartridges and arcade cabinets.

Today however, they are more akin to directory structures found when browsing a PC/Mac rather than binary dumps of a single chip.   If you're emulating the GC for example, it's more appropriate to call the games you're emulating "images" - "disc images".