There were times when storing data was an big issue. It was difficult to manage very important documents as there were no good facilities, but today with the advant of the technology a small device can store large number of data and that device is USB.
A USB flash drive — also known as a USB stick, USB thumb drive or pen drive — is a plug-and-play portable storage device that uses flash memory and is lightweight enough to attach to a keychain. A USB flash drive can be used in place of a compact disc. When a user plugs the flash memory device into the USB port, the computer’s operating system (OS) recognises the device as a removable drive and assigns it a drive letter.
The first USB flash drive came on the market in 2000 with a storage capacity of 8 megabytes (MB). Drives now come in capacities ranging between 8 gigabytes (GB) and 1 terabyte (TB), depending on manufacturer, and future capacity levels are expected to reach 2 TB.
Common uses of USB flash drives are for storage, supplementary back-ups, and transferring of computer files. Compared with floppy disks or CDs, they are smaller, faster, have significantly more capacity, and are more durable due to a lack of moving parts. Additionally, they are less vulnerable to electromagnetic interference than floppy disks, and are unharmed by surface scratches.
Until about 2005, most desktop and laptop computers were supplied with floppy disk drives in addition to USB ports, but floppy disk drives became obsolete after widespread adoption of USB ports.
USB flash drives use the USB mass storage device class standard, supported natively by modern operating systems such as Windows, Linux, macOS and other systems.
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 rubberized case, which can be carried in a pocket or on a key chain, for example. Some are equipped with an I/O indication LED that lights up or blinks upon access.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.
Flash drives are often measured by the rate at which they transfer data. Transfer rates may be given in megabytes per second, megabits per second or in optical drive multipliers.
On a USB flash drive, one end of the device is fitted with a single USB plug; some flash drives additionally offer a micro USB plug, facilitating data transfers between different devices.
Computers access modern flash memory systems very much like hard disk drives, where the controller system has full control over where information is actually stored. The actual EEPROM writing and erasure processes are, however, still very similar to the earlier systems.
Semiconductor corporations have worked to reduce the cost of the components in a flash drive by integrating various flash drive functions in a single chip, thereby reducing the part-count and overall package-cost.