Data on digital media may be destroyed, intentionally or inadvertently, in a number of ways.
Data may be wiped, which generally means flipping all the ones to zeros (or possibly vice versa). Such wiping is device-dependent, since flipping ones to zeros on a spinning magnetic disk requires writing zeros, while performing the same action on flash media is an erase operation and not technically a write operation.
Overwriting data is similar to wiping it, although overwriting makes explicit the action of writing new data to the location of the old. The overwriting data may be a pattern, random, or data copied from elsewhere, and such overwrites may be performed multiple times to further reduce the chance of old data recovery.
Older spinning magnetic disks often sustained head drift over time, theoretically leaving a shadow of old data even after overwriting. Repeated overwrites were meant to mitigate this risk, although such recoveries were not widely reported and are believed to be currently impossible due to modern spinning disk density and precision.
Disk corruption may occur through environmental or physical damage to storage media and may affect part or all of a media's storage area. Such corruption may physically destroy all aspects of the data (metadata, file system information, and data contents), or may only corrupt part of the data (such as removing a file system entry but leaving the data intact).
Degaussing is the application of a strong magnetic field to a magnetic disk drive for the purposes of resetting the magnetic charge on the surface of the disk platters. The strong magnetic field will set all charge the same, effectively erasing any stored data.