Nintendo 64, super Nintendo, Nintendo, Nintendo wii, play station 1, play station 2, play station 3, xbox, xbox 360, atari, sega genesis, gamecube, sega Saturn, sega CD, game boy, game boy color,...
a laser etched in a code in the shiny part of the disk and every console has a reader that reads the code it first started as a cartridge and the game was a huge code that was stored in the cartridge
It's worth whatever anyone will give you for it. Value is base on, condition, availability, and location. It could be worth anywhere from $20 to $5000. Just depends on who wants it and how much...