When you lose the information, which was once accessible is referred as data loss.

There are two types of Data Loss.

1. Logical Data Loss
2. Physical Data Loss

Logical Data Loss: Hard drive that is physically functioning, recognized by the system BIOS, and where critical data is not accessible, is likely to be experiencing a logical failure.

1. Logical Data Loss is caused due to:
   • Human error, including accidental deletion of files.
   • Virus attack.
   • Software malfunction.
   • Power surge.
   • Sabotage.
2. Physical Data Loss happens due to various reasons such as:
   • Hardware failure (electrical, mechanical component), including damage by power surge and drive failure.
   • Natural disasters like floods, fire, lightning.
   • Accidental dropping of disk to the floor also may cause hard disk getting damaged physically.