BIOS

• BIOS stands for Basic Input / Output System.
• BIOS is also known as Legacy BIOS.
• Name itself says that, it controls the basic operation of PC hardware.
• BIOS setup acts as a interface between processor and operating system.
• BIOS setup utility allows you to change the boot process order.
• BIOS setup allows you to set the hardware.(If you are beginner don't touch the hardware settings).
• You can open BIOS by pressing F2 or F1 or F11 or Del or ESC depends on the mother board operator.
• BIOS works when we start PC.
• Below figure shows the BIOS steps. 

• Below are the options present in the BIOS
• Advanced BIOS  Faeatures
• Advanced Chipset Features
• MB Intelligent Tweaker(M.I.T)
• Integrated Peripherals.
• PC Health Status.
• Set User Password.
• Set Supervisor Password.
• Load Optimized Defaults.

Locating BIOS on Mother Board

• BIOS is situated beside the CMOS returning BIOS or B-BIOS or M-BIOS on mother board.
• In other way we can locate by a paint mark on the BIOS chip.

Limitations of BIOS

• It can only run 16bits at a time.
• Can only run 1MB of process at a time.
• It can only boot from below 2.1 TB.
• There is no better interface.

Implementation of UEFI BIOS

• Due to less size working of BIOS, Implemented UEFI increasing hardware size.
• UEFI stands for Unified Extended Firmware Interface Modem.
• UEFI is features:
• It can handle data more than the 2 TB disk.(Limits 9.4 Zetta Byte)
• It run with 32 bits or 64 bits.
• Uses secure boot setup.

Some difference between BIOS and UEFI

Legacy BIOS	UEFI
Uses Assembler for Programming.	Uses C-Language for Programming.
Option ROMs to store memory.	Uses Drivers to store memory.
Uses Master Boot Record(MBR) for recording the booting details.	Uses GUID Partiton table (GPT) for recording the booting details.
No operation for mouse.	We can mouse to operate.

Checking BIOS Type:

• Open RUN (Win + R).
• Type MsInfo32.
• Check BIOS Mode.