Almost all data is stored on electronic media like hard drives, RAIDs, SSDs, external hard drives, CDs and DVDs, flash memory and other removable media. When you lose data stored on your storage media - it can be quite unpleasant. It can take time to recreate the lost article or to restore a database. But often it concerns millions of dollars, someone's reputation or something else that is extremely valuable. The reason for losing of the files can belong to any kind of human errors, natural disasters, unpredictable accidents or disruption of the gadget.
The first thing you should remember: nearly all data can be recovered. No doubt, there are cases when the damage of the device is so bad that files are lost irrevocably, but in most ordinary cases, it is possible to retrieve them. This is not an easy business, there needs to be specific experience, precise equipment, and strong skills.