CD-ROMs typically don’t degrade. CD-Rs and such do. CD-ROMs have physical pits etched into the plastic, as do mass-produced DVDs and BDs. These advantages don’

CD-ROMs typically don’t degrade. CD-Rs and such do. CD-ROMs have physical pits etched into the plastic, as do mass-produced DVDs and BDs. These advantages don’t apply to discs you produce yourself, however. It can happen, but it’s rare—not so rare that I forgo backups, but rare enough that I continue to maintain an archive of actual CD-ROMs.