BIOS (Basic Input/Output System): The BIOS is firmware stored in a dedicated memory chip on a computer’s motherboard that initializes and tests hardware components during startup. It performs a Power-On Self-Test (POST) to verify that essential components, such as memory and drives, are functioning correctly. Once these initial checks are complete, the BIOS locates and loads the operating system’s bootloader, allowing the OS to take control of the machine.
Users can access the BIOS setup utility by pressing a designated key (e.g., F2, Del) during startup, where they can configure settings like boot order, system time, and security options. These settings are stored in non-volatile memory, ensuring they persist even when the system is powered off.
Modern systems often use UEFI (Unified Extensible Firmware Interface), which builds on BIOS functionality with additional features such as faster boot times and support for larger drives.