Simple Breakdown: Emulators are the Game Console and ROMS are the games. You can use the two together to play your favorite classics on your PC.
Emulators
Go here if you are looking for something to play video game roms on your computer. (Think of an emulator as a video game console or system.)
Cick here For Emulators
Roms
Click here if you have an emulator and are looking for more games to play on it.
Click here For ROMs