Apple iMac - using disk images with the .mds extension - .mdf

Since I am a novice user, I have accordingly encountered problems that I am gradually trying to solve. One of them is the inability to use disk images with the .mds extension - .mdf on a poppy. There is an opinion that you can simply rename mdf to iso, but somehow I am skeptical about it. Otherwise, why all this garden with two files, if everything is so simple ... To convert, I found the program MISO-J . It picks up the .mds file (respectively with .mdf) and converts everything into one iso. Next - a matter of technology ...

ps there is no Windows on the Mac, so I was looking for a solution for poppy