What is BIOS ?
- BIOS stands for Basic Input/output System, the BIOS is a ROM chip located on all motherboards that allows us to access and set up our computer system at the most basic level.
- The BIOS includes instructions on how to load basic computer hardware and includes a test referred to as a POST (Power On Self-Test) that helps verify the computer meets requirements to boot up properly.
- If the computer does not pass the POST, we will receive a combination of beeps indicating what is malfunctioning within the computer.
- The BIOS loads when our computer starts up, and the BIOS is responsible for waking up our computer’s hardware components, ensures they’re functioning properly, and then runs the bootloader that boots operating system we have installed.
Main functions of BIOS:
- POST : BIOS will run the power on self test to test computer hardware is properly functioning before starting process of loading Operating System.
- Bootstrap Loader : Process of locating the operating system. If capable Operating system located BIOS will pass the control to it.
- BIOS : Software / Drivers which interfaces between the operating system and our hardware. When running Windows we are using complete BIOS support.
- CMOS Setup : Configuration program. Which allows us to configure hardware settings including system settings such as computer passwords, time, and date.
What is UEFI ?
UEFI or Unified Extensible Firmware Interface is based on a technology developed by Intel. It is installed at the time of manufacturing and is the first program that runs when a computer is turned on.
Difference between BIOS and UEFI ?
- UEFI is the successor to BIOS. It can boot from drives of 2.2 TB or larger theoretical limit is 9.4 zettabytes.
- UEFI can run in 32-bit or 64-bit mode and has more addressable address space than BIOS, which means our boot process is faster.
- UEFI is more user friendly i.e., it uses more animations and pictures and we can use mouse in bios it is not possible.
- UEFI is more secured than BIOS.