How data is organized on a magnetic disk?

         Before the computer can use a magnetic disk to store data,the disk's surface must be magnetically mapped so that the computer can go directly to a specific point on it without searching through data.(because a magnetic disk drive's heads can go directly to any point on the disk's surface to read or write data,magnetic storage devices are also categorized as random access storage devices)The process of making a disk called formatting or initializing.
        When you purchase new diskettes or high capacity floppy disks,they should already be formatted and ready to use with your computer.In a new computer the built  in hard disk is almost always already formatted and has software installed on it.If you buy a new hard disk by itself ,however you may need to format it your self but this is not difficult to do.
        You may find it helpful to reformat diskettes from time to time,because the process ensures that all existing data is deleted  from the disk.During the formatting process ,you can determine whether the disk's surface has faulty spots,and you can copy important system files to the disk.You can format a floppy disk by using operating system commands.