Rom/rɑːm/ Definition 1 of 2Pro Tip 1/3Non-Volatile Memory ROM is permanent; it keeps data even when the device is turned off. Your game console has ROM that saves the firmware. Pro Tip 2/3Not Editable Unlike RAM, you cannot modify information stored in ROM. The game's ROM can't be changed to add new levels. Pro Tip 3/3Predetermined Data ROM comes with data preinstalled, which is necessary for the device to run. Your calculator's functions are stored in its ROM.