If the hard disk drive fails, using a floppy disk with the start-up files on it may be the only method of booting the computer. It's a good idea to have one or two disks like this for emergencies, but if you format all your disks this way, you'll take up space on your diskettes that could be used for other information. A new blank disk purchased from a store contains a thin, circular piece of plastic, covered with a magnetic material, similar to audio tape. If you try to read from or write to it on the computer, the disk drive will spin briefly and then tell you that the disk is unreadable. The process of organizing a blank, empty disk, so that it can be recognized by the computer and be used to store data, is called formatting.
Some companies do sell pre-formatted diskettes.
Most disk manufacturers will sell the disks unformatted so that they can be used on different types of computers. Each type of computer system stores information differently, so they need to format disks in their own way. You can re-format a disk that is formatted for a different system, however, any information already on the disk will be permanently lost. The computer checks to see if the diskette is usable. The diskette is divided into sectors and tracks.