Format

The organization of information according to preset specifications. In digital audio and computer applications it pertains to the dividing of media into marked segments and determining how data will be arranged on it. The process known as formatting prepares a storage medium, usually a disk, to record data. In this process, the drive writes special information onto the recording surface(s) in order to divide it into areas (called blocks) that are ready to accept user data. When you format a disk, the operating system erases all bookkeeping information on the disk, tests the disk to make sure all sectors are reliable, marks any bad sectors, and creates internal address tables that it later uses to locate information. On many systems it is possible to perform either a high level or low level format. A high-level format generally only erases the address tables of a disk, which makes it appear to be blank even though the data hasn’t been erased. Hard disks also have a low-level format, which sets certain properties of the disk such as the interleave factor. The low-level format also determines things like what type of disk controller can access the disk and, last but not least, does zero all data.