BIOS stands for Basic Input-Output System. It is the first software that runs when you turn on your computer.

Think of the BIOS as the starter🚗 of your PC. It is not stored on the hard drive like Windows or macOS, but rather on a permanent memory (ROM) chip on the motherboard.

Its function is to "wake up" the computer's hardware and prepare it to load the main operating system.

Its basic tasks include:

1. POST (Power-On Self-Test): Performs a quick diagnostic to check if essential components such as RAM, processor, and video card are working.

2. Initialization: Identifies and initializes connected peripherals, such as keyboard, mouse, and hard drives.

3. Loading the Operating System: Locates the operating system (on the HDD, SSD, or USB drive) and delivers it to the processor so that it can begin loading.

The BIOS also contains a settings panel ("setup") that allows the user to adjust low-level hardware parameters.

In modern computers, the BIOS has been largely replaced by a more advanced, graphical system called UEFI, but the fundamental function remains the same.