Although all the "technical" answers others have given are likely correct... I really suspect the majority of modern computer users use the terms because of the following: Disk = short for diskette, refers to floppies, and when a hard drive is called a "disk" is used for that as well simply because that is what floppies were called at the time hard drives became cheaper and more mainstream. Disc = CD or DVD. Not short of anything per se, but is taken right off the offical Compact Disc logo. For whatever reason, Sony et al decided to use "disc" for CDs. That is the way the packages and logos are written for CDs and now usually for DVDs as well. Nothing more complex or deep rooted then that. People use the spelling they see on the packages in front of them. Floppies almost always say "Disk" and CDs always (it is part of the offical logo) say "Disc". From there, users interchange them from time to time because they simply don't know what is correct or even why each are the way they are. -chris <http://www.mythtech.net>