An SSD (solid-state drive or solid-state disk) is a nonvolatile storage device that stores persistent data on solid-state flash memory.
SSDs actually aren't hard drives at all in the traditional sense of the term, as there are no moving parts involved. Instead, an SSD has an array of semiconductor memory organized as a disk drive, using integrated circuits (ICs) rather than magnetic or optical storage media. This arrangement has many advantages. Data transfer to and from solid-state drives is much faster than electromechanical disk drives. Seek time and latency are also substantially reduced and end users typically enjoy much faster boot times as well. In general, SSDs are also more durable and much quieter, with no moving parts to break or spin up or down. SSDs have a set life expectancy, however, as they have a finite number of write cycles before performance becomes erratic.