Answer:Boot device priority is the order in which a computer checks different storage devices when starting up. It determines which device the system will attempt to boot from first, such as a hard drive, SSD, USB, or CD/DVD. The user can modify this order through the computer's BIOS or UEFI settings. For example, if a USB is set as the top priority, the computer will boot from it if it contains a valid operating system. Changing the priority can be useful when installing a new OS or troubleshooting boot issues.