What Does External Hard Drive Mean?
An external hard drive is a storage device located outside of a computer that is connected through a USB cable or wireless connection. An external hard drive is usually used to store media that a user needs to be portable, for backups, and when the internal drive of the computer is already at its full memory capacity. These devices have a high storage capacity compared to flash drives and are mostly used for backing up numerous computer files or serving as a network drive to store shared content.
Techopedia Explains External Hard Drive
Two interfaces are usually used by this storage device: FireWire or USB. The difference between these interfaces is the rate at which data can be transferred. USB connections can move data at a rate of 12 to 480 Mbps (megabits per second), while FireWire supported external devices boast transmission speeds ranging from 400 to 800 Mbps. Newer external hard drives are now USB 3.0 and 4.0 ready, although most PCs and laptops do not even support USB 3.0 yet.