Data recovery is a process of salvaging (retrieving) inaccessible, lost, damaged or formatted data from storage, removable media or files. The data is most often recovered from storage media and other electronic devices. Recovery may be required due to physical damage to the storage devices or logical damage to the file system.
In one scenario, files have been accidentally "deleted" from a storage medium by the users. Typically, the contents of deleted files are not removed immediately from the physical drive. In the mind of end users, deleted files cannot be discovered through a standard file manager, but the deleted data still technically exists on the physical drive. In the meantime, the original file contents remain.
Another scenario involves a drive-level failure, such as a compromised file system or drive partition, or a hard disk drive failure. In any of these cases, the data is not easily read from the media devices. Depending on the situation, solutions involve repairing the logical file system, partition table or master boot record, or updating the firmware or drive recovery techniques ranging from software-based recovery of corrupted data, hardware and software-based recovery of damaged service areas (also known as the hard disk drive's "firmware"), to hardware replacement on a physically damaged drive which involves changing the parts of the damaged drive to make the data in a readable form and can be copied to a new drive. If a drive recovery is necessary, the drive itself has typically failed permanently, and the focus is rather on a one-time recovery, salvaging whatever data can be read.