What is an SSD?

An SSD stores information in electronic memory rather than on moving magnetic platters. Most use NAND flash, retaining data without power. Operating systems, applications and documents can be stored on an SSD. Persistent storage is still vulnerable to hardware failure and accidental deletion.

How do HDD, SATA, NVMe and M.2 differ?

An HDD reads rotating magnetic platters; an SSD has no moving read head, which can reduce delays particularly for small, scattered accesses. SATA is an interface standard, while NVMe is an access protocol commonly using PCIe. M.2 describes a physical format and connector arrangement, so not every M.2 drive uses NVMe. Drives with equal capacities can have different speeds, controllers and endurance characteristics. Sequential speed measured with large files is not the same as random-access behaviour involved in opening applications.

How should lifespan, capacity and data protection be understood?

Flash cells have finite write endurance, and controllers use techniques such as wear distribution and error correction. Endurance figures describe specified conditions, not an exact failure date. Free space, temperature, write intensity and interface bandwidth can affect performance. Important files need separate backups; encryption and suitable erasure methods matter when transferring or disposing of drives. Deleting a file alone does not establish that every physical cell is free of traces. Additional storage capacity also does not remove processor or network bottlenecks.