Learn in the textbookAuxiliary Storage and Flash Media — HDD, SSD, USB, SD
DefinitionAn SSD is an auxiliary storage device that records data in flash memory and has no parts that spin or move.
ExplanationIt is a non-volatile device that keeps its contents when the power is off, and in the memory hierarchy it counts as auxiliary storage. It reads and writes by addressing the data's location electrically, so there is no waiting for a head to move or a platter to turn as in an HDD.
AnalogyPicture the same kind of chips found in a USB flash drive, fixed inside the PC and scaled up to a much larger capacity.
Memory hookSolid State refers to a solid physical state, signaling that the device has no moving mechanical parts and is made only of solid electronic components.