USB Flash Drive

A USB flash drive, also known as a USB key, is a small data storage device used for transferring data between computers. It typically takes the form of a keychain or pendant and is equipped with flash memory, which retains data even when power is disconnected. Data is transferred to the memory via the USB interface, hence the name. Despite sometimes being referred to as a "disk," USB flash drives have no moving parts. USB flash drives are the successors to floppy disks and optical disks. Their advantages include smaller size, lighter weight (most weigh less than 30 grams) and greater durability and reliability. Unlike floppy disks, they are immune to magnetic fields, and unlike CDs, they are not affected by surface scratches. USB flash drives use the USB Mass Storage standard, which is supported by all commonly used operating systems and devices such as game consoles, DVD players, smartphones, tablets, and computers. A typical flash drive consists of a small printed circuit board with integrated circuits, enclosed in a plastic, metal, or rubberized case for protection. It includes a control unit for memory communication with the PC, a memory chip for data storage, and a crystal that generates the main clock signal (originally 12 MHz). Additional features may include a technical connector for production testing or firmware recording, an LED indicator to show data activity, and a lock or switch for enabling write protection.