While classic cartridge-based systems use simple .rom or .bin files, disc-based systems like the Wii require specific file formats to handle the large amounts of data stored on a DVD. Understanding File Formats: ISO vs. WBFS
Risks and responsibilities
Years ago, external hard drives had to be entirely formatted to a volatile "WBFS partition" that Windows computers couldn't read without special software. Today, that method is completely obsolete. Wii Roms Wbfs Europe