<P> A USB flash drive, also variously known as a thumb drive, pen drive, jump drive, disk key, disk on key, flash - drive, memory stick or USB memory, is a data storage device that includes flash memory with an integrated USB interface . It is typically removable, rewritable and much smaller than an optical disc . Most weigh less than an ounce (approx . 30g). Since first appearing on the market in late 2000, as with virtually all other computer memory devices, storage capacities have risen while prices have dropped . As of March 2016, flash drives with anywhere from 8 to 256 GB are frequently sold; less frequent are 512 GB and 1 TB units . Storage capacities as large as 2 TB are planned, with steady improvements in size and price per capacity expected . Some allow up to 100,000 write / erase cycles, depending on the exact type of memory chip used, and are thought to last between 10 and 100 years under normal circumstances . shelf storage time . </P> <P> USB flash drives are often used for the same purposes for which floppy disks or CDs were once used; i.e. 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 . </P> <P> USB flash drives use the USB mass storage device class standard, supported natively by modern operating systems such as Windows, Linux, macOS and other Unix - like systems, as well as many BIOS boot ROMs . USB drives with USB 2.0 support can store more data and transfer faster than much larger optical disc drives like CD - RW or DVD - RW drives and can be read by many other systems such as the Xbox 360, PlayStation 3, DVD players, automobile entertainment systems, and in a number of handheld devices such as smartphones and tablet computers, though the electronically similar SD card is better suited for those devices . </P> <P> A flash drive consists of a small printed circuit board carrying the circuit elements and a USB connector, insulated electrically and protected inside a plastic, metal, or rubberised case, which can be carried in a pocket or on a key chain, for example . The USB connector may be protected by a removable cap or by retracting into the body of the drive, although it is not likely to be damaged if unprotected . Most flash drives use a standard type - A USB connection allowing connection with a port on a personal computer, but drives for other interfaces also exist . USB flash drives draw power from the computer via the USB connection . Some devices combine the functionality of a portable media player with USB flash storage; they require a battery only when used to play music on the go . </P>

What type of port is used by flash drives