Data disposal methods are techniques and tools used to delete or destroy data when it reaches the end of its retention period or is no longer needed. Depending on the type of data, storage medium, and security level, there are various methods that can be employed. Deletion is a common approach, but does not guarantee complete erasure; deleted data can still be recovered unless it is overwritten. Overwriting replaces data with random or meaningless information, making it unreadable and unrecoverable. This technique can be done with software or hardware tools, such as shredders or degaussers. Encryption transforms the data into an unreadable format using a secret key or algorithm; this can be done with software or hardware tools as well. Lastly, physical destruction damages or destroys the physical storage medium, such as hard drives, disks, tapes, or paper documents; this can be done with tools like hammers, drills, shredders, incinerators, or magnets.