You're looking for information on Wii games and WBFS ( Wii Backup File System)!
, which is a 1:1 disc copy, a WBFS file "scrubs" unneeded data (like update partitions) to significantly reduce file size without losing game data LaunchBox Community Forums Essential Tools & Methods Wii Backup Manager: wii games wbfs
| Game Example | ISO Size (Raw) | WBFS Size (Trimmed) | Savings | | :--- | :--- | :--- | :--- | | Super Smash Bros. Brawl | 8.5 GB (Dual Layer) | ~6.9 GB | 19% | | Mario Kart Wii | 4.7 GB | ~3.3 GB | 30% | | New Super Mario Bros. Wii | 4.7 GB | ~350 MB! | 92% | You're looking for information on Wii games and
: Unlike a raw ISO (always 4.37 GB), WBFS files are "scrubbed." They remove "garbage data" and padding used to fill physical discs, meaning a game like Wii Sports might only take up ~600 MB in WBFS format. The File System Wii | 4