Flash memory can be erased, and it generally is faster than other types of storage because no moving parts are involved. Flash memory retains information even when powered down, in contrast to the RAM of a computer. It's possible to overwrite flash memory many times.
SSD (solid-state drive) usually includes flash memory, but will also have additional components. NAND 'NOT AND', is form of flash storage used in removable flash drives and SSDs. Data can only be rewritten on a NAND a limited number of times.
Hard disk drive
1. A SSD device does not include any moving parts. It differs from a hard disk drive (HDD) which stores information on spinning disks.
2. SSDs are more expensive than HDDs.
3. Data can be accessed on SSDs more quickly.
4. SSDs are sturdier than HDDs.
5. HDDs can retain data longer than SSDs, which tend to lose data after about 2 years.
6. SSDs use less power than HDDs.