Each ZIP file contains every file needed for that specific game, including parent files and BIOS.
If you are new, start with a small "non-merged" set of just the top 50 classic games for 0.261. Downloading a 100 GB full set is overkill for most users. Mame 0.261 Full Roms
Setting up a collection of this size requires specialized tools to ensure the ROMs match the emulator version. Essential Tools Each ZIP file contains every file needed for