Overwritten or Loss Data Recovery
When information is erased from a computer hard drive, it is not actually erased. Whether you are deleting a file from the recycle bin or formatting the drive, all of the information is still stored on the computer hard drive. Instead of being removed, what happens is that the information is no longer listed in the computer’s File Allocation Tables (FAT). This tells the computer that the space is available to be used for something else. When something new gets placed in that sector of the hard drive, it is referred to as being overwritten.
If you have accidentally overwritten an important data with a new one, actually you still have a chance to recover photo, video's files that was overwritten. Amazing, right? We can try to recover up to 90% overwritten data by accident but this process complicated and time taking.