Data recovery is the process of restoring data that has been lost, corrupted, or deleted. When a file is deleted, it is usually not physically erased from the disk, but only marked as free space by the operating system.
Therefore, it may be possible to recover the file by using specialized tools that scan the disk for the file's data.
However, if the file has been overwritten by another file or data, then the original file's data is lost and cannot be recovered. The other options are not as challenging as overwriting, because they only affect the logical structure of the disk, not the physical data. For example, the partition table, the directory, and the formatting information can be reconstructed or bypassed by using forensic tools. References = CISM Review Manual,
16th Edition, Chapter 5, Section 5.4.1.2