External memory refers to any form of storage device that can be connected to a computer or other electronic device to expand its storage capacity. This can include devices such as external hard drives, USB flash drives, memory cards, and more. External memory is essential for storing large files, backing up important data, and transferring files between different devices. It provides a convenient and portable solution for managing and accessing data that may not fit on the device's internal storage. External memory devices come in a variety of sizes, speeds, and capacities to suit different needs and preferences.