What is disk corruption?

Disk corruption is the general term used when data stored on the computer is lost due to a mechanical hardware failure.

Disk corruption in hard disks is usually due to the disk head crashing into the disk, on which the data is encoded, cause permanent and irreversible loss of data. Also means a part of a file may be partially affected. This makes the particular file 'corrupt' and cannot be used as data will be completely or partially lost.