A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory. And functions as secondary storage in the hierarchy of computer storage. It is also sometimes called a semiconductor storage device, a solid-state device, or a solid-state disk. Even though SSDs lack the physical spinning disks and movable read-write heads used in hard disk drives (HDDs) and floppy disks. SSD also has rich internal parallelism for data processing.

In comparison to hard disk drives and similar electromechanical media which use moving parts. SSDs are typically more resistant to physical shock, run silently, and have higher input/output rates and lower latency. SSDs store data in semiconductor cells. As of 2019, cells can contain between 1 and 4 bits of data. SSD storage devices vary in their properties according to the number of bits stored in each cell. With single-bit cells (“Single Level Cells” or “SLC”) being generally the most reliable. Durable, fast, and expensive type, compared with 2- and 3-bit cells (“Multi-Level Cells/MLC” and “Triple-Level Cells/TLC”). And finally, quad-bit cells (“QLC”) being used for consumer devices that do not require such extreme properties and are the cheapest per gigabyte (GB) of the four.