Disc or Disk?

Fact: they are not the same thing.

After always feeling confused when I wrote the word 'disc' or 'disk,' I finally decided to look it up. The results were educational.

A disc contains optical data, encoded in binary format on the surface of the disc as a series of non-reflective pits (0) and reflective lands (1). The information on a disc is retrieved when the disc is spun and illuminated with a laser diode. Examples include: CDs, laser discs (remember these?), DVDs, mini-discs (remember these?), and Blu-ray discs.

The term disk refers to a broader category of data storage devices that stores digital information on rotating platters by magnetic, optical, or physical means. So, a disc is always a disk, but in many cases, a disk is not a disc. Got it? Some examples are hard disk drives and floppy disks (remember those?).

The hard disk drive was a substantial upgrade from magnetic tape which had been used prior to its advent. Now, it is only a matter of time before solid state drives (your USB drive is a prominent example) replace hard disk drives for most consumer use.

Congratulations! We've learned something today.

Questions for Discussion:

1. Which obsolete media storage technology do you miss? Laser discs? Casette tapes? Beta-max?
2. Was this disc vs. disk question weighing on you as heavily as it weighed on me?