wait, what are you talking about? a mini disk looks if anything like a floppy drive. It is square plastic, and inside that square plastic is a small disk, similar to a CD.
There are also small CD's, which they give out for free when you get the "super-sized soda" or whatever. That is a CD, just smaller (maybe a 2 inch diameter instead of 4). The first is a mini disk, it can hold more data (hours of music) then a CD can. The second one is a CD, just smaller. Its exactly like a CD, except that since its smaller it holds less data (less music).