Floppy Disk

Floppy disks are made of Mylar (a plastic material) coated with magnetic material (iron oxide or barium ferrite). Floppy disk is a soft magnetic disk, rather it is a very thin piece of flexible plastic, it is called floppy disk because its disk can be bent unlike hard disk. Floppydisks are also called diskette. They are removable disks. The floppy drive is a computer component to read/write from or to the floppy disk. Unlike hard disk, floppy disk can be removed from the floppy drive. The floppy (or flexible) disk is kept within a plastic jacket. A metallic shutter protects the media access hole. The drive manipulates the shutter, leaving it closed whenever the disk is not in a drive. So, the media is completely insulated from the environment and from user's fingers.
Different sizes of floppy disks are:5.25 inch diameter. It was 8 inch in diameter when it was invented. A floppy disk rotates at about 300 rpm. Its average access time is 150-250 ms.

Inch Floppy Disk
The 3.5 inch floppy disk's read/write head window is covered with a sliding metal cover that is a metal shield. The disk drive pushes the cover aside when a disk is inserted into the drive unit. There is a hole at the centre for drive spindle. There is a write-protect notch to protect the stored information. It uses a sliding plastic button, which can slide to either of the two positions. One position allows reading, writing and erasing. The other position allows only reading. When light is visible through the notch, then only the disk is write protected. The protective cover of a 3.5 inch floppy is hard plastic. The storing capacity of a 3.5 inch high density floppy is 1.44MB. It uses 80 tracks per surface, 135 TPI (tracks per inch), 18 sectors per track, 360 rpm and store 512 bytes per sector. Both sides of the disk store information.