[bmacho]

> In most varieties of English, disk is the preferred spelling for magnetic media (hence floppy disk, hard disk, disk drive), whereas disc is preferred for optical media (hence compact disc, digital versatile disc, optical disc).

> For all other uses, disk is preferred in American English and acceptable in Canadian English, and disc otherwise.

https://en.wiktionary.org/wiki/disk#Usage_notes

[Markoff]

> In most varieties of English, disk is the preferred spelling for magnetic media (hence floppy disk, hard disk, disk drive), whereas disc is preferred for optical media (hence compact disc, digital versatile disc, optical disc).

that's exactly my understanding as a non-native English speaker who haven't even read the article :-)

in my native language, they both share same word - disk (hard disk, compact disk), though floppy disk had it's own word

[sandworm101]

Also, disk is also used in "diskette", whereas disc stands alone. So as magnetic disks shrank and were called disketts on and off, they kept that spelling. Optical discs never really shrank over the years, never being called discettes.

[oneplane]

When they shrank the disc it just became minidisc ;-) But that was technically MO, not just optical. And: it was in a cartridge so I suppose they really should have called it minidisk.

[karmakaze]

It's all photons baby, sometimes virtual.