A flash drive and a pen drive perform the same essential function; however, many people confuse the terms. Colloquially, people may refer to a flash drive and pen drive as if they are the same device. This is due to the fact that all pen drives are flash drives. That being said, it is important to note that flash drives have usages that extend beyond the capabilities of a pen drive.
The major difference between a pen drive and flash drive is that a pen drive is generally only used as a mobile USB storage device, whereas a flash drive has many different uses for data storage. Another difference is that the pen drive always refers to a drive that can be plugged directly into a USB port. On the other hand, a flash drive may be accessible by a direct USB connection, a corded USB connection, or even stored internally inside a cell phone or mobile media device.
Generally speaking, a flash drive is any data storage device that holds data with non-movable parts. Before the inception of flash drives, computer users used floppy discs and CDs to store small amounts of data. When a computer user inserts a disk or CD into a computer, the computer reads the devices through movable parts, such as a laser scanning a CD. Since the flash drive has no moving parts, it is less susceptible to damage. Another advantage of the flash drive is that it is almost universally compatible with a variety of devices. To transfer data between two devices both devices need to have a USB port or USB adapter, but most contemporary computers and electronic products have a USB port. This means that in addition to providing backup storage on a computer flash drives can also be used to store information from video game consoles, mobile media devices, and cellular phones.
The pen drive is a type of flash drive named for its small pen-like appearance. Pen drives can be inserted directly into a USB port without a USB cord. Due to its lack of a cord, a pen drive is extremely mobile and can be attached to a key chain or put in your pocket.
According to the Phison company website, the term "pen drive" came into the computer vocabulary in 2001. Phison developed a removable data storage device they named "pen drive." Since then, a pen drive has incorrectly been synonymous with all USB flash drives.