What function does a usb key perform?

A USB key, also known as a USB flash drive, serves as a portable storage device that allows users to store, transfer, and back up data. It connects to computers and other devices via a USB port, enabling easy access to files such as documents, photos, and videos. Additionally, USB keys can be used for software installation, data recovery, and even booting operating systems. Their compact size and ease of use make them popular for personal and professional data management.