What is the difference between BIOS and UEFI?

Speaking about the computers, It's more important to know what the BIOS is. That is why I got an idea to write a blog about the difference between BIOS and UEFI.

What is BIOS?

The BIOS is special software that interfaces the major hardware components of your computer with the operating system. BIOS stands for Basic Input Output System. Simply BIOS is a Firmware that stored on a BIOS chip which is non volatile. It is mainly responsible for initializing of your Hardware to use it in a manner.

What does the BIOS do?

When you turn on your computer, the BIOS does several things.
Its usual sequence are as follows.

1. Check the CMOS Setup for custom / user settings
2. Load the interrupt handlers and device drivers
3. Initialize registers and power management
4. Perform the power-on self-test (POST)
5. Display system settings
6. Determine which devices are bootable
7. Initiate the bootstrap sequence

Have you heard about the CMOS Battery? A tiny battery that looks like a Remote Battery which has 1.5 V as input voltage. Yes! The setting are kept on CMOS chip by CMOS battery.

The traditional BIOS still has serious limitations. It can only boot from drives of 2.1 TB or less. 3 TB drives are now common, and a computer with a BIOS can’t boot from them. That limitation is due to the way the BIOS’s Master Boot Record (MBR) system works.

What is UEFI?

Here the UEFI is introduced which stands for Unified Extensible Firmware Interface. The vast majority of computers you can buy today now use UEFI rather than a traditional BIOS. Because not just like a single blue screen with only keyboard support, it supports many colors with Animations. Even you can use a mouse to select the options.

Also it has a feature called Security Boot, To ensure that no malware or malicious program has tampered with the boot process.

In few words, BIOS is a Firmware which is stored in a BIOS chip and Its settings are stored in a CMOS chip which is volatile uses CMOS battery to pretend like non volatile. And UEFI is expected to eventually replace BIOS.

That's all. These are the few more basic difference between the BIOS and the UEFI. Let me know if it is useful or not by just posting comments below. If you like share it on Facebook with your friends.