MDF - Media Disc Image File is a special type of formatting that can be used to save different information right onto your DVD or even your CD. You will have to make sure that you use a program to give you added support. Alcohol 120% will make a very good use. This type of file has many comparisons to .ISO even though it is saved totally different. The MDF file is what the data uses to save all of the information. You will be able to keep track of information about the files using the header.