Before answering this question let’s discuss
what is BIOS. BIOS is a firmware that starts the operating system during boot up. It plays an important role in your system, hence it is not possible for computer to function without BIOS because it initializes hardware and launches the operating system, a computer cannot operate without it. Crucial functions carried out by BIOS include bootloader loading, Power-On Self-Test (POST) execution, and hardware component detection. The system couldn't boot up or operate correctly without BIOS since it wouldn't know how to interface with main parts like the CPU, RAM, or storage.
