A bad sector on a hard drive is simply a tiny cluster of storage space — a sector — of the hard drive that appears to be defective. The sector won’t respond to read or write requests.
Bad sectors can occur on both traditional magnetic hard drives and modern solid-state drives. There are two types of bad sectors — one resulting from physical damage that can’t be repaired, and one resulting from software errors that can be fixed.
There are two types of bad sectors — often divided into “physical” and “logical” bad sectors or “hard” and “soft” bad sectors.
Causes of Hard Bad Sectors:
Your hard drive may have shipped from the factory with bad sectors.
Causes of Soft Bad Sectors:
Soft bad sectors are caused by software issues.
Data Loss and Hard Drive Failure
The reality of bad sectors brings home a chilling fact — even if your hard drive is otherwise working properly, it’s possible for a bad sector to develop and corrupt some of your data.