A pen drive is another term for USB (Universal Serial Bus) flash drive and is basically a data storage device. The pen drive was invented in 1998 by IBM, with the intention of replacing the floppy drive in its ThinkPad line of products. The first flash drive was manufactured by M-systems under contract with IBM and was called the disgo. The disgo came in various sizes: 8 MB, 16 MB, 32 MB and 64 MB. Following the launch of disgo, a number of pen drives of different sizes, types and brands came into the market. Today, pen drives are used in a range of devices such as mobile phones, video-game consoles and digital-music players.