The files stored on your computer are typical written onto the drive, which consists of thin, round platters coated with a bright magnetic data storage medium, much like the fordatarecovery shiny coating on the thin ribbons contained inside VHS and cassette tapes. Exactly like in a VCR or a tape player, ahead within your computer's drive reads and writes the data onto the magnetic storage medium. Whenever you delete a file on your computer, it is not actually erased from the hard drive. The drive simply changes the marker on that space from "occupied" to "vacant." The information itself is still there until it is written over. Think of it as a property video that you have decided you don't want anymore. Until you actually tape over it, it's still there.