Data sanitization is an integral part of secure data management, which is typically required when you need to dispose of your hard drive to throw away an old system. This is done by overwriting the drive multiple times to remove all the evidences of data remanence in your system, i.e. making data completely unrecoverable.
So you think that by formatting the hard drive of your computer, you have completely deleted all your crucial files and personal information from it and you now can consider it ready to be sold. If yes, then you are wrong! There are various specialized data recovery tools available by which one can recover