The vast majority of audio editing in Pro Tools is nondestructive. Whether cutting, pasting, trimming, separating, or clearing clips, you are only performing these functions on a map of the actual media (such as audio files). The source files remain untouched. However, certain processes or tools work destructively (can permanently change audio files on your hard disk), as noted in other topics.While editing for MIDI tracks is in some instances destructive, with a few precautions you can keep important MIDI tracks and clips safe when performing edits (see Nondestructive MIDI Editing).