Answer : 4. "Portable storage device"
Explanation :

. Flash memory is a portable storage device that can store data for a short period of time.

2. Unlike traditional hard drives, flash memory is capable of retaining data even after the power is turned off.

3. A flash drive is a small, portable flash memory card that plugs into a computer's USB port and acts as a portable hard drive.

4. A flash drive is a portable data storage device. Flash drives contain multiple flash chips, which are large memory modules.