What are the Functions of BIOS in Computer System?

The BIOS is the primary software which runs as soon as computer starts also load important files into the memory for further usability and functionality, the main functions of BIOS in computer system is to recognize all the computer peripheral devices like RAM, Processor, keyboard, mouse, harddisk, DVD-RW and their configurations, it also load important operating system files to the memory.

The BIOS is known as Basic Input Output System. 

BIOS is situated on the motherboard and is considered as one of the important chip.

The BIOS is a firmware device which is responsible to provide boot-up or startup process. It also checks the hardware and its configuration to diagnose its working status.

The BIOS is considered to be an vital and crucial part of any computer system.

What is BIOS [Basic Input Output System] in Computer System?

BIOS stand for Basic Input Output System. The first screen appears on the computer after starting is known as BIOS or PC BIOS.

It is software embedded in the motherboard and executes when the computer starts; the RAM, processor, keyboard, and hard drive are configured when the BIOS computer is turned on.

Our computer’s memory is situated on ROM, which knows every component of the computer BIOS and, therefore, can boot the computer’s operating system.

BIOS check the CMOS settings you have provided and decide which device the system will be booted.

What is BIOS
What is BIOS

After preparing its entire task sequentially, they call the operating system when computer boots.

The BIOS is already installed; later the program is installed on the CPU, and ROM, which is non-volatile memory.

EEPROM stands for (Electronically Erasable Programmable Read-Only Memory) this type of memory cannot be deleted.

If in any case we need to update BIOS then this chip or memory can be reprogrammed to derive the desired results.

4 Functions of BIOS in Computer System

  • CMOS and BIOS first check the settings between each other; later the computer is turned on, all settings in CMOS are read and executed.
  • The BIOS then loads a computer driver to interface between the operating system and connected devices.
  • BIOS then clean up all the CPU registers and make them ready for use.
  • Afterward, the BIOS check all the hardware devices, including the keyboard and mouse, and test them, a process known as POST or Power-on Self-Test.
  • During the POST process, you press a special key with the help of keyboard by which a set of settings appear in front of you, which is known as the BIOS setting.
  • This is the first setting that the BIOS load.
  • Later finds a BOOTABLE medium, it loads essential files into the RAM, and then the computer is on, and we are able to view the desktop.

Famous BIOS & Firmware Manufacturing Companies?

American MegatrendsPhoenix

Uses of BIOS

#Uses of BIOS
1Power on Self-Test [POST].
2 Recognize and configure hard ware devices.
3Interrupt handlers and loads device driver.
4Load operating system into memory.
5Check and change boot order.
6Display any errors while start up.

What is the Most Important Function of the BIOS?

BIOS check the CMOS settings after starting the computer. They read the settings of the CMOS, to check whether everything is functioning correctly.

 After checking BIOS setting BIOS load computer driver which works as interface between the operating system and connected device.

 After loading the computer driver, it starts all CPU registers are ready to work correctly.

After all this process, BIOS finds a bootable medium after reading the bootable medium, and they load the correct file to the RAM just after the computer is on. 

How Does BIOS Work Step by Step?

How BIOS work:

The main function of BIOS is to boot the operating system of the computer. When the computer is on, then BIOS does this tasks given below.

  • For the custom setting, you can check the CMOS setup.
  • To load the Interrupt handlers and device driver.
  • To conduct Power-on-self-test (POST).
  • For display system settings.
  • To decide from which device system is the boot.

What is Difference Between BIOS and CMOS?

Difference Between BIOS and CMOS
Difference Between BIOS and CMOS
BIOS Stands for Basic Input Output SystemCMOS’s full name is Complementary Metal Oxide Semiconductor.
BIOS configure the input-output of the computer, store all settings, and start the computer.CMOS work is in the form of battery and to secure all settings of BIOS.
BOIS is known as Computer Boot Process Start-up.CMOS is known by its other name, like Real Time Clock (RTC), Non-volatile RAM (NVRAM), or CMOS RAM,
BIOS Software are installed in motherboard’s EEPROM (Electronically Erasable Programmable Read-Only Memory) is stored on the ROM chip.The CMOS battery is small coin shaped cell on the motherboard,
Their work is incomplete without each other if CMOS is damaged or corrupted, then BIOS still works,If BIOS is damaged, then CMOS stops responding.
BIOS gets power from CMOS.CR2032 cell battery gives power to CMOS which is also called CMOS battery
The BIOS stores and handle all the data and information previously given to them.CMOS battery saves data and information given to them and they do not tend to lose data and information even computer restarts.

After turning the computer off, the data and time always display the correct versions, this is because the CMOS battery is running at the back end which is capable of storing data and information fed to them.

How to Access BIOS?

Press F2, F12, Delete, or Esc key; every PC has different keys for BIOS. It changes with manufacturers.

How to Configure BIOS?

After performing the above step of BIOS, there are numerous furthermore settings which are used for accomplishing specific task and operations.

In this BIOS setting some of the options are standard which does not have to be changed. This options are pre-installed with BIOS manufacturers.

BIOS setup utility screen are divided into five parts: Main, Advanced, Power, Boot, and Exit, and in every section, there are different options.

If you are updating the BIOS setting, one should be very careful about the changes, for changes arrow and tab key are used and utilized.

For changing important items, page up and page down are used and in the last to save these changes F10 key is used.

Is BIOS Software or Firmware?

Firmware is also the type of software that is used to control hardware and also used to communicate between hardware and software.

The firmware is stored in ROM.

The firmware is a type of software which is embedded in hardware, The firmware are preinstalled into hardware device while manufacturing.

The majority of the electronic appliances uses firmware for better usability and functionality, In almost every firmware hardware’s basic functionality is embedded therefore a firmware can be called as hardware or software.

Is BIOS Application Software?

BIOS is a software program which is attached or installed in a hardware or chip, and this chip is installed on motherboard.

As soon as we press the power key from CPU the BIOS functionality starts. The major functions of BIOS is to

Configure RAM, Processor, Keyboard, hard disk, etc.

This is present on your ROM memory, which is known all hardware device BIOS is used to boot the computer’s operating system, and BIOS is already present on the computer.

Related Articles

What are the 3 Common keys Used to Access the BIOS?

There are given some keys of BIOS:
  • Laptop: F1, F2, Enter then F1, F10, F12, DEL
  • Desktop Personal Computer: F2, Esc, Del, Delete, Enter
  • Microsoft Surface Tablets: Press and hold the volume up button

Who Manufactures the BIOS for Your Computer?

BIOS are pre-installed on the computer by the manufacturer; new version can be obtained by updating the BIOS,

Frequently Asked Question [FAQs]

Why Do We Use BIOS?

The main function of the BIOS is to check the hardware and startup process, and loading the operating system into the memory.

Is BIOS a Software or Hardware?

The BIOS is a software programs which is embedded in the chip and are correlated with hardware and other devices.

Is BIOS a Software or Firmware?

BIOS is a firmware.

Is BIOS a Operating System?

No it is not an operating system.


BIOS is a ROM [Read Only Memory].

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