Disk Formatting and Low level formatting of floppy disks

Disk formatting is the initial part of the process for preparing a hard disk or other storage medium for its first use. The disk formatting includes setting up an empty file system. A disk formatting may setup multiple file systems by formatting partitions for each file system. Disk formatting is also part of a process involving rebuilding an entire disk from scratch.

There are two steps involved in formatting magnetic media such as floppy disks and hard disks.

Low-level formatting of floppy disks : The first step involves the creation of the actual structures on the surface of the media that are used to hold the data. This means recording the tracks and marking the start of each sector on each track. This is called low-level formatting, and sometimes is called "true formatting" since it is actually recording the format that will be used to store information on the disk. Once the floppy disk has been low-level formatted, the locations of the tracks on the disk are fixed in place. Since floppies use a stepper motor to drive the head actuator, the floppy drive must be aligned properly in order to read the tracks on the disk. Sometimes the heads of a particular drive can become out of alignment relative to where they should be; when this happens you may notice that a disk formatted on the misaligned drive will work in that drive but not in others, and vice-versa.
Since floppy disks tend to be put together cheaply these days and many of them are getting rather old, it is generally preferable to always low-level format a disk in the drive you plan to use to write to it.