A portion of a
disk that cannot be used because it is flawed. When you
format a disk, the
operating system identifies any bad sectors on the disk and marks them so they will not be used. If a
sector that already contains
data becomes damaged, you will need special
software to recover the data.
It’s not unusual for a hard disk to leave the manufacturing process with a damaged sector; however, this does not affect the overall performance of the disk as the damaged space is considered unusable.