An NDS file contains a game ROM of a video game for the Nintendo DS (NDS) handheld gaming console. It contains the same data as the original NDS game cartridge and can be played in Windows, macOS, Linux, or Android with a Nintendo DS emulator.
NDS files are typically used by gamers who enjoy playing retro, discontinued games on their computers. The gamers may create NDS files by dumping the game data from the original cartridge onto a computer and packaging it as an NDS file. Or gamers may download NDS files from game emulator websites that have already been dumped from game cartridges.
There are a variety of emulators available for playing NDS games, including DeSmuME, NO$GBA, iDeaS Emulator, OpenEmu, and Exophase DraStic DS Emulator. Some features provided by emulators include enhanced game graphics, helpful gameplay settings, and new "cheat" options.
NOTE: The NDS was released in 2004 and uses two screens, one of which that is touch-sensitive. DS stands for "Dual Screen."