BIOS shadow
Updated: 10/07/2019 by Computer Hope
The term BIOS shadow is the copying of ROM (random-access memory) contents to the RAM, where the information may be accessed quickly by the CPU (central processing unit). This copy process is also known as Shadow BIOS ROM, Shadow Memory, and Shadow RAM.
The examples below are messages you might see when the computer first boots. They indicate that portions of ROM (read-only memory) are being copied to the system RAM.
System BIOS shadowed Video BIOS shadowed
Some computer BIOS setups may allow the user to enable and disable this feature. We recommend keeping it enabled; disabling this option could cause problems with some computers.