What type of memory chip do most solid-state drives use to store data persistently?

Most solid-state drives use flash memory, specifically NAND flash, to store data persistently. NAND flash stores bits by trapping electric charge inside tiny transistor cells, and because that trapped charge stays put even after power is removed, the drive keeps its data without needing a battery or any moving parts.

Dynamic RAM, or DRAM, is volatile memory that loses its contents the instant power is cut, so it's used for fast temporary working memory, not long-term storage. Magnetic core memory is an old computing technology from decades ago that has been replaced entirely by newer approaches like flash.

Because flash memory cells gradually wear out after a limited number of write cycles, SSD controllers use a technique called wear leveling to spread writes evenly across all the cells, which helps the drive last much longer than it otherwise would.