is a portable memory storage device. It is a re-writeable storage device, which can store the memory data without a power supply unlike RAM. Thumb drive can fit into any USB port on a computer. It is also known as flash drive. A user can plug the drive into a computer and will not have to restart it to access the thumb drive. The drives are small in size like a human thumb and are very stable memory storage device. The thumb drive is available in storage size of up to 8 gigabytes.