There must be a time when we really need to recover the data that we save, maybe sometimes a various of failure happen to our hard drive or memory card so that we need to recover data. Generally, there are 2 kind of damage that can impact our hardware that is physical damage and logical damage.
In physical damaged hardware, sometimes to recover the data we just need to replace parts in the hard disk. A logical damaged hardware can make the hard drive unreadable, to recover it we need to repair the damaged filesystem using a data recovery software.
Beside that, there are many other types of recovering data, such as RAID (Redundant Array of Independent Disk) recovery, NAS recovery and so on. We need to pay attention to our hardware and always check it to anticipate the damage might happen.