Reference

MDF/MDS (disc image)

MDF/MDS is a disc-image format created by Alcohol 120%. The MDF holds the actual disc data while the matching MDS file stores the layout and metadata, together preserving a CD or DVD as a file you can mount or burn.

Files & formatsGeneral

MDF/MDS (disc image)

Also known as: MDF file, MDS file, Alcohol disc image, .mdf .mds

Disc-image format from Alcohol 120%
MDF holds data; MDS holds the disc layout
Both files needed; convert to ISO for compatibility

A two-file disc image

MDF/MDS splits a disc image into two parts: the .mdf contains the raw track data copied from the disc, and the .mds describes the disc structure — sessions, tracks, and layout.

Both files are needed together. The format originated with the Alcohol 120% disc-imaging software and can capture copy-protection details that a plain ISO cannot.

Opening MDF/MDS files

Disc tools like Alcohol 120%, DAEMON Tools, and some converters mount or burn MDF/MDS images. For broad compatibility, you can often convert an MDF to a standard ISO.

Related terms

Keep reading the reference.

Files & formatsISO (disk image)An ISO file is a disk image — an exact, single-file copy of an optical disc (CD/DVD) or its file system. You typically mount it as a virtual drive or extract its contents, rather than "installing" the ISO itself.General Files & formatsDisk imageA disk image is a single file that mirrors the entire contents of a disk or volume — its file system, structure, and data. Common types include ISO (discs), DMG (macOS), and IMG. You mount or write a disk image rather than just extracting files from it.General Files & formatsDMG (Apple disk image)A DMG is Apple’s disk-image format, used mainly to distribute Mac apps. You double-click it to mount a virtual drive, drag the app to Applications, then eject and delete the .dmg — you do not "install" the DMG itself.macOSGeneral