ROMs are games that you can use on downloaded emulators. These games are usually licensed. A lot of good ROMs (unpopular games, games exclusively released in Japan) can be quite hard to find, knowing how most sites give you a ton of bullshit and forced voting, but no ROMs. Emulation and ROMs are the only way I have access to great Japanese SNES games such as Super Wrestle Angels, YuuYuu Hakusho Tokubetuhen, Sanrio World Smash Ball!, and Super Puyo Puyo 2 Remix.
Jeff: He is such a ROM.