A 1TB external hard disk drive is a portable storage device that offers 1 terabyte (1,000 gigabytes) of storage capacity. It is designed to be connected to a computer or other device via a USB cable, allowing users to easily transfer and store large amounts of data, such as documents, photos, videos, and music. External hard drives are commonly used for backing up important files, expanding storage capacity, and transporting data between different devices. The 1TB capacity provides ample storage space for most users’ needs, making it a convenient and versatile storage solution.