Flash memory is widely used in SSDs, smartphones and memory cards because it stores data without power, is compact and performs faster than mechanical hard drives. However, it remains more expensive per gigabyte than hard disks, degrades with repeated writes and erases, and cannot match the speed of system RAM.

Modern NAND technology increases capacity through vertical 3D stacking and multi-bit TLC and QLC cells, although denser designs can reduce endurance and performance. SSD controllers mitigate these limits through wear levelling, error correction, spare capacity and data-management processes; Samsung, for example, warrants its 1TB 990 Pro for five years or 600TB written. Hard drives remain cheaper for large-scale storage, while NAND prices are forecast to rise amid constrained supply and AI and data-centre demand; no alternative memory technology has yet displaced NAND.