An external hard disk is a compact, self-contained storage unit encased in a protective housing. It typically consists of one or more hard disk drives (HDDs) or solid-state drives (SSDs) housed within the enclosure.

Features:

1. Storage Capacity: External hard disks are available in various storage capacities, ranging from a few hundred gigabytes (GB) to several terabytes (TB).
2. Connectivity Options: External hard disks typically connect to devices via high-speed interfaces such as USB (Universal Serial Bus), Thunderbolt, or eSATA .
3. Portability: External hard disks are designed to be portable, allowing users to carry them easily between different locations. They are compact and lightweight, making them ideal for mobile professionals, students, photographers
4. Plug-and-Play: Most external hard disks are plug-and-play devices, meaning they can be connected to a computer.
5. Backup and Storage Solutions: External hard disks are commonly used for data backup and storage purposes.
6. Security Features: Some external hard disks come with built-in encryption.