A disk is a flat circle; subject in the form of a flat circle. / Wikipedia /
Despite the shape of the body in the form of a paralepide, we call the hard disk "disk". Because the disk itself is spinning inside :) There are also drives in which information is not ontologically stored on a hard (inflexible, hard) disk (flat circle), but in flash memory cells of one type or another. Some perverts continue to call such drives " solid-state hard drives " or simply " solid-state drives ."
Imagine if this picture was written Solid State Disk Drive (: ')
We must call a spade a spade. "Solid State Drive" .