USB flash drive

        

           A USB flash drive is a data storage device comprising a flash memory integrated with a USB bus (Universal Serial Interface). USB flash drives are typically removable and rewritable, and physically much smaller than a floppy disk. Most weigh less than 30 g (1 ounce). September 2011 [update] 256 GB units are available, and the storage capacity of up to 2 terabytes are provided with steady improvements in size and price for the design capacity. Some allow up to 100,000 write / erase cycles (depending on the exact type of memory chips used) and 10 years of storage platform.
     USB flash drives are often used for the same purpose for which they were used floppy disks or CD-ROM. They are smaller, faster, thousands of times more capacity, and are durable and reliable, because they have no moving parts. Until about 2005, most computers were involved, and floppy drives, floppy drives, but left the USB port.
USB flash drives use the USB mass storage standard, supported natively by modern operating systems like Linux, Mac OS X, Windows and other Unix-like systems. USB drives with USB 2.0 can store more information and to move more quickly than larger units optical discs such as CD-RW or DVD-RW, and can be read by many other systems, such as the Xbox 360 , PlayStation 3, DVD players and some of the future Mobile smartphones.
     Nothing moves mechanically on a flash drive: the term drive persists because computers read and write flash drive data using the same system commands than a mechanical hard drive with the storage appearing in computer operating system and user interface as any other player. Flash drives are very robust mechanically.
A flash drive consists of a small printed circuit board carrying the circuit elements and a USB connector, electrically isolated and protected within a plastic, metal, or rubber case can be carried in a pocket or on a keychain, for example. The USB connector can be protected by a removable cap or by retracting into the body of the unit, although it is not likely to be damaged if not protected. Most flash drives use a type of a standard USB connection that allows connection to a port of a PC, but it is difficult for other interfaces are also available.
    USB flash drives are powered by the computer via a USB external. Some devices combine the functionality of a digital audio player, USB flash memory, which require a battery when used to play music.