CHD is currently the gold standard for Sega Saturn emulation.
File Organization: Instead of a folder containing 50+ tracks (common for Saturn games with heavy CD audio), you get one single .chd file per game.
Most Saturn games you find online are in Redump format. Redump is a preservation project that creates perfect 1:1 copies of discs. For the Saturn, that usually means:
In a hobby often cluttered with file extensions and technical hurdles, the CHD is a rare example of technology making things simpler, smaller, and better. For the modern Saturn fan, it is the only format that matters.