What are Mini Discs?
MiniDiscs were announced in 1991 by Sony as a small disc based digital medium for recording audio in “near CD” quality. The disc itself is enclosed in a small (7cm x 7cm), convenient, cartridge. MD is a recordable format, you can record on a MD the same way you can record on a cassette. The primary difference between MD and cassette is that MD is a digital audio format and is read optically, with a laser, just like a CD.