A USB flash drive, also known as a USB drive, USB memory or USB stick, [a] is a data storage device that includes flash memory with an integrated USB interface. USB flash drives are usually removable and rewritable, and physically much smaller than an optical disc. Most weigh less than 30 grams (1.1 oz). Since its first appearance in the market in late 2000, as with virtually all computer memory devices, storage capacities have increased while prices have fallen. As of March 2016, flash drives with anywhere from 8 to 256 GB are sold frequently, and less frequently 512 GB and 1 TB drives. Storage capacities of up to 2 TB are planned, with continuous improvements in size and price per expected capacity. Some allow up to 100,000 write / delete cycles, depending on the exact type of memory chip used, and have a storage period of 10 years.
USB flash drives are frequently used for the same purposes for which floppy disks or CDs were used; That is, for storage, data backup 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. In addition, they are immune to electromagnetic interference (as opposed to floppy disks), and are not damaged by surface scratches (as opposed to CDs). Until 2005, most desktops and laptops shipped with floppy drives as well as USB ports, but floppy drives have become obsolete following the widespread adoption of USB ports and the larger capacity of the USB drive compared With the 1.44-by-3.5-inch disk.
USB flash drives use the standard USB mass storage device class, compatible with 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 drives such as CD-RW or DVD-RW drives and can be read by many other systems like Xbox 360, PlayStation 3, players DVD, car entertainment, and a number of portable devices such as smart phones and tablet computers, although the SD card similar to electronics is more suitable for those devices.
A flash drive consists of a small printed circuit board that carries circuit elements and a USB connector, insulated electrically and protected inside a plastic, metal or rubber case that can be carried in a pocket or on a key ring, for example . The USB connector may be protected by a removable or retracting cover on the body of the unit, but is not likely to be damaged if it is not protected. Most flash drives use a standard USB Type A connection that allows connection to a port on a personal computer, but there are also drives for other interfaces. USB flash drives extract power from the computer through 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 along the way.
It can be understood in the following video: