SSD stands for solid-state drive. It stores data in semiconductor memory and does not use the moving read/write mechanism found in a hard disk drive. SSD describes the storage device; SATA and NVMe describe different interface or communication technologies that an SSD may use.
Simple explanation
An SSD is the part of a computer or storage device that keeps the operating system, applications and files even when power is removed. It uses electronic memory rather than spinning magnetic platters.
Because no read/write head has to move to a physical location, solid-state storage can respond quickly and operate silently. Capacity, controller, memory type, interface, cooling and workload still affect the behaviour of a particular drive.
Technical context
SSD is a device category, not one connector. A 2.5-inch SSD commonly uses SATA. An M.2 SSD may use SATA or PCI Express, and an NVMe SSD uses the NVMe specification for communication with non-volatile memory over a supported transport such as PCI Express.
The host system must support the drive's form factor, physical size, keying, interface and firmware requirements. Visual similarity alone is not proof of compatibility.
Example in a buying decision
If a laptop manual says it accepts an M.2 2280 PCIe NVMe drive, “M.2” describes the card format and size family while “PCIe NVMe” describes the supported connection and communication path. A visually similar M.2 SATA drive may not be the correct choice.
Sources and further reading
Technical statements were reviewed against these references. External pages may change after our review date.
- Hard disk drive versus solid-state drive — IBM
- NVMe set of specifications overview — NVM Express
- The SATA ecosystem — Serial ATA International Organization