External drives · When the drive is unplugged
If my Mac's internal drive fails, are the files I moved to the external drive safe?
Short answer: Yes. Moved files are ordinary files on the external drive, so they survive a Mac failure and open on any Mac. Only the shortcuts are lost; copy what you need back in Finder and reinstall apps fresh.
Yes — what's on the external drive lives on the external drive. Moved files are ordinary files and folders there, so they survive a problem with your Mac and can be opened or copied on any other Mac.
What you lose with the Mac are the shortcuts that pointed to them. On a repaired or new Mac you can copy what you need back from the drive's Storage Studio folder in Finder. Apps moved to the drive are best reinstalled fresh on the new Mac rather than run from the old copy.