• The MDS file extension refers to Media Descriptor Files, which are categorized as disc image files. They are information files that describe the formatting of a CD or a DVD. MDS files usually correspond with an ISO file or an MDF file which contains actual data from the disc. It is similar to a CUE file, which describes the data stored on a BIN file.
  
  

ISO Files

• ISO files are Disc Image Files which contain the exact replica of the data from the original disc. They correspond with MDS files; MDS files contain formatting data, while ISO files contain the audio and video data.
  
  

MDF Files

• The MDF file is a Media Disc Image file. It is similar to an ISO file, but saved in a different format. The MDF file contains actual disc data, while the MDS file contains the formatting data.
  
  

CUE Files

• CUE files are Cue Sheet files; these are text files that define the way tracks are organized on CDs and DVDs. They contain format data for a disc, similar to MDS files.