Basic Input Output System( BIOS)

BIOS stands for Basic Input Output System. It is a small software program built into a computer’s motherboard. When you turn on your computer, BIOS is the first software that runs, even before your operating system (like Windows, Linux, etc.) starts.

BIOS is a firmware program that is used to start the computer system. There are two types of BIOS, they are:

• Legacy BIOS
• UEFI( Unified Extensible Firmware Interface)

BIOS is responsible for:

• • Booting up the computer

  • Checking hardware components like RAM, CPU, keyboard, etc. (called POST – Power-On Self-Test)

  • Loading the operating system from a storage device (like a hard drive or SSD)

  • Providing a setup utility to change system settings (like boot order, system time, etc.)

BIOS Functions

The main functions of BIOS are as follows.

• POST (Power-On Self-Test):
  Checks hardware components to ensure everything is working.

• Bootstrap Loader:
  Finds and loads the operating system from the boot device.

• BIOS Setup Utility:
  Allows users to configure hardware settings using the BIOS menu.

• CMOS Setup:
  Stores settings like date, time, and boot sequence.

• Drivers:
  Provides basic drivers to operate keyboard, display, and storage devices before the OS loads.