NES, Nintendo (NES) ROM File (.nes)
The NES Misc file format
NES files are binary files containing game data from Nintendo Entertainment System video games. These files are commonly known as game ROMS for the NES console. Different emulators for several platforms can play these ROMs, allowing the user to play popular 8-bit NES games on their Windows or Linux computer or Mac.
Technical details of NES files
The NES game ROMS contain a duplication of the game data of the real, physical NES game cartridge. Depending on the emulator used, video as well as audio data of the game may appear with small errors. This occurs because the performance of a NES ROM differs across different emulators. A choppy NES file may play perfectly in a different emulator.