What is the primary function of the Basic Input/Output System (BIOS)?

The primary function of the Basic Input/Output System (BIOS) is to ensure the computer runs the same program every time it is turned on. BIOS is a firmware that initializes and tests hardware components during the booting process and provides a runtime environment for the operating system to load. Specifically, it performs POST (Power-On Self-Test) to check hardware function before handing over control to the operating system. This consistent initiation of the hardware and subsequent loading of the operating system is what allows the computer to operate reliably every time it's powered on.

Other options do not represent the core functions of BIOS. Updating software programs regularly is typically the function of operating systems or specific update management software, while storing user preferences and settings is usually managed by the operating system or specific applications. Network connection management is primarily handled by network interface cards (NICs) and related networking software components rather than by the BIOS itself.