What is the primary function of BIOS in a computer system?

The primary function of BIOS, or Basic Input/Output System, in a computer system is to launch the operating system. When a computer is powered on, the BIOS is the first software that runs from the motherboard's firmware. It performs a series of essential tasks, including hardware initialization and testing (often called POST, or Power-On Self Test) and loading the bootloader that starts the operating system.

Once the hardware has been checked and initialized, the BIOS locates the operating system on a storage device and loads it into the computer's memory, allowing the system to operate as intended. This process is crucial because without BIOS, the computer would not be able to start up and execute programs effectively.

Other options, such as enhancing graphics performance, managing internet connectivity, or optimizing power consumption, do not fall within the primary responsibilities of the BIOS. These functions are typically managed by other components of the computer system, like the graphics card, network interface card, and power management features of the operating system.