In a nut-shell, the BIOS (Basic Input/Output System) is one of those aspects of your computer that you might never need to pay any attention to. As long as it’s running smoothly, you may not even know your BIOS is there, unless you manage to catch a glimpse of it in action as your PC is booting up.

The BIOS is responsible for making sure that all the hardware in your computer is powered up and ready to go. It initializes a checklist during system boot up (called a POST or Power-On Self Test) and ensures that all of the pieces of your PC are able to communicate with each other before letting your operating system take over.

Your BIOS runs in flash memory built into the motherboard and is similar to the firmware that exists in hardware such as graphics cards and printers. It’s not software that exists completely in machine language, but it’s not altogether unalterable either. You can make changes to the BIOS that are then saved into that flash memory, and those changes will take effect after you reboot your system.