USB flash drive is a portable storage device. It is often the size of a human thumb , and it connects to a computer via a USB port. Flash drives are an easy way to transfer and store information, and they are available in sizes ranging from 2 GB to 1 TB.
USB flash drives are often used for storage, data back-up and transfer of computer files. They are smaller, faster, have thousands of times more capacity, and are more durable and reliable because they have no moving parts. Additionally, they are immune to electromagnetic interference (unlike floppy disks), and are unharmed by surface scratches (unlike CDs). Until about 2005, most desktop and laptop computers were supplied with floppy disk drives in addition to USB ports, but floppy disk drives have become obsolete after widespread adoption of USB ports and the larger USB drive capacity compared to the 1.44 MB 3.5-inch floppy disk.