What Does Bad Sector Mean?
A bad sector is an unusable part or subdivision within a track on a magnetic or optical disc located on a computer’s hard disk or flash drive. It typically forms as a result of physical damage or, rarely, the operating system’s (OS) inability to access the information.
Techopedia Explains Bad Sector
Several spare sectors are located in modern hard drives. The firmware of a disk controller identifies bad sectors and remaps them to a different physical sector. When a bad sector is pinpointed, automatic remapping occurs; this automated process typically takes place when a sector is overwritten. The sector is never reused. Instead, the drive controller just removes the sector address from the list of usable storage locations in ROM.
