The British spelling was used by Philips when they launched the Compact Disc with Sony.

Disk was used by American companies inventing hard disks, floppy disks etc.

British software often used "disc" for both, e.g. RISC OS on Acorn/ARM/Raspberry Pi [1].

[1] https://arcwiki.org.uk/index.php/RISC_OS_3 (see screenshot)

Apple uses “disk” when referring to SSD storage. They still use disc when referring to a CD or DVD

Source: the language used in MacOS Tahoe

SSD could stand for "SSD Storage Device".

Bring back recursive acronyms!

SSD, of course, stands for Solid State Dis[c,k]...