BIOS Stands for “Basic Input/Output System.” The BIOS is a program pre-installed on Windows-based computers (not on Macs) that the computer uses to start up. The CPU accesses the BIOS even before the operating system is loaded. The BIOS then checks all your hardware connections and locates all your devices. If everything is OK, the BIOS loads the operating system into the computer’s memory and finishes the boot-up process. It is located in the ROM (Read-Only Memory) of the computer. More specifically, it resides in an eraseable programmable read-only memory (EPROM) chip.
The BIOS also is used after the computer has booted up. It acts as an intermediary between the CPU and the I/O (input/output) devices.
