USB means Universal Serial Bus. USB flash driveconsists offlash memorydata storage deviceintegrated with a USB1.1or2.0interfaces and are typically removable and rewritable. USB drives are much smaller than a floppy disk. It is light weight almost 30 g which is lesser than a floppy disk. It can storeup to 256 GB with steady improvements in size and price per capacity out of which some allow 1 million write or erase cycles. The data retention cycle is 10 years. Capacities in USB Drives like 4 GB USB DRIVE, 8GB USB DRIVE, and 128 GB USB DRIVE etc is available in the market.
These flash drives are often used for the same purposes asfloppy diskswere but are smaller, faster and have thousands of times more capacity, and are more durability as compared to floppy disk. Due to lack of moving parts they are also more reliable. 4 GB USB DRIVE stores double the data of 2 GB. Till the year 2005 most of the desktops and laptop computers were supplied with floppy disc drives which are replaced by USB drives now. USB mass storage standard is used by Flash drives which is supported by modern operating systems such as Windows Linux, UNIX and Mac.
In a flash drive nothing moves mechanically the term drive persists because computers read and write flash drive data using the same system commands as a mechanical disk drive. They are very robust mechanically, and can withstand anything that does not actually break the circuit board. 4 GB USB drives consists of small printed circuit board carrying the circuit elements and a USB connector which is insulated electrically and protected inside a plastic, metal or rubberized case. SanDisk Cruzer Mini 4 GB USB flash drive is available for 50 $.