A .smw file is a ROM (Read-Only Memory) image of the Super Mario World video game, originally released for the Super Nintendo Entertainment System (SNES). These files contain a complete copy of the game's data, including the game's code, graphics, music, and level designs. They are typically used with emulators, which are software programs that allow users to play SNES games on computers, smartphones, or other devices. Due to copyright restrictions, distributing or downloading ROMs of commercial games without owning the original game cartridge is generally considered illegal. However, ROMs are sometimes used for archival purposes or by game developers for research and modification. The .smw extension specifically identifies the file as a Super Mario World ROM, allowing emulators to recognize and load the game correctly. Modders also use .smw files as a base for creating custom levels and hacks for Super Mario World, often using specialized tools to edit the game's data within the ROM.